I am having a challenging time researching the Dhamma difference between Anger and Ill-will; Ill-will specifically in reference to the lower fetters.
Can someone help me better understand the distinction?
Additionally, I would like to better understand if one can uproot the fetter of Ill-Will but still experience moments of anger (in its various flavours, such as frustration, impatience, etc).
Thoughts?
At least in English to have ill will is to be angry at someone else, to bear ill will is to be holding on to anger at a person.
Anger in general doesnāt have to be directed at anyone, we can stub our toe or forget our groceries and be angry without being angry at a person.
For me, Ill will involves hanging on to your āenemyā thinking.
One wants to harm the āenemyā the one or the other way.
One is not looking for a peaceful solution and/or giving the other person a fair chance.
One is āstuck in a thought processā.
It can also be directed towards an animal.
Anger can be directed at everything. Even a traffic light or the computer. It doesnāt necessarily involves the wish of harming. It can be short lived.
Both are deeply engraved in our minds and need to be uprooted. The cause needs to be found (followed back) and contemplated.
Ill will: a work mate who embarrassed you in front of everyone. The thought of wanting to harm him arises. The thoughts gets faster and meaner, stories start to create . At one point you are not even acknowledging him anymore. You are unable to talk to him and to keep up a normal work relationship. He on the other hand has forgotten it 10 minutes later.
Anger: A person rushes pass you and you fall. Anger arises, due to pain and the personās mindlessness. The person turns around, apologises and helps you up. Your anger dissolves.
I hope this helps 
There are many words in the suttas to describe the broad variety of mental experiences that you are interested in.
Usually, hatred and ill will are synonymous in English and that seems well founded from the Pali, but I wouldnt say the same for ill-will and anger either in English or in the Pali. However, both can be contained under the root defilement of Dosa, and also with the underlying tendancy (anusaya) of Patigha of aversion or resistance.
In terms of the lower fetters itās worth noting that mostly in the suttas the 5th lower fetter is ByÄpÄda but in the Abhidhamma (Dhs. 1113-34) we have Patigha instead, which is often translated as anger in that context. Unfortunately, many writers often incorrectly substitute Patigha for ByÄpÄda and so we have the ongoing confusion of āangerā being a lower fetter when that is not the case in the suttas.
Something I often emphasise in teachings about ill will, hate anger etc is to avoid the unrealistic expectation that we can just expect these things to be uprooted easily - beware the tendencies of spiritual bypassing (emotional numbing, anger phobia, toxic positivity, deluded belief of attainments) which folks in spiritual communities often idealistically gravitate toward, creating unrealistic expectations of themselves and others.
Afterall, the fetter of ill-will is not completely overcome till the 3rd stage of enlightenment - non-returner (or anagami) stage. This is an incredibly high stage of development, just one step away from full liberation (or arahantship). So, itās unrealistic to expect that us ordinary, everyday people wont still have a bit of ill will or anger from time to time.
The analogy I often use to help people put this in perspective is that of a trip to the moon. We are stuck on earth and getting to the moon is hard. If arahantship is stepping on the moon, then anagami, when ill will is eradicated completely, is touchdown in the lunar lander. Before that was getting into lunar orbit (once returner, where ill-will is substantially reduced) and before that we needed a HUGE amount of energy and fuel to escape earth orbit - stream entry. This took a massive amount of effort and understanding of complex ideas, but yet there is still ill will in the mind! And, most of us are still back here looking up at the sky, with no inkling of how to get into space at all. A few of us might be drawing cartoons of rockets, or if we are lucky, reading instructions (the Buddhaās teachings) on how to build a rocket at university or perhaps working for NASA. But the sad truth is that certainly most of us will never get into space in this lifetimeā¦ so if people get a little angry or hostile from time to time, we can understand why - like us, they are a long long long way from the moonā¦
To me, anger is less of a problem that resentment, grudge, malice, malevolence etc because these things are thoughts that we let percolate inside us, returning to over and over, deepening and cementing that hate. But anger is usually something more specific, spontaneous and, therefore, hopefully more short lived.
A good example of this is the Lekha Sutta An3.132 where three types of angry person (in this case the Pali is khujjati) are compared to inscriptions - the first is an inscription carved into rock (holds on to anger for a long time), the second is an inscription in sand (holds on for a lesser time) but the best is the third, a line drawn in the water - which disappears almost as soon as it is drawn, which is how we should practice. We donāt have the unreasonable expectation that anger wont arise in us (it will) but when it does, itās *how * we deal with it that matters most- letting it go quickly.
See below for some terms in the Buddhist thoughtscape of aversion/hate/ill-will.
Dosa: Aversion, Hatred,
ByÄpÄda / VyÄpÄda: Ill-will, malice, malevolence
one the Five Hindrances (nivarana)
one of the Ten Fetters (samyojana),
one of the Defilements (kilesa)
one of the 3 Wrong Intentions (asankappa)
one of the 16 Defilements (upakkilesa)
Patigha: repugnance, grudge, resentment, anger
one of the Nine Latent Tendencies (anusayas) and one of the Abhidhammaās list of the 10 fetters, coming in at number 2 on the list. ByÄpÄda is absent in this version.
Kodha: anger (one of the upakilesas)
kujjhati gets/becomes angry with, cross with something
Vera: enmity, hatred
Vihiį¹sÄ: cruelty, harm, hurting, one of the 3 unwholesome intentions
UpanÄha: hostility, hatred
ÄghÄta: resentment, ill will
Can good-will never be a cause for anger?
Or, can anger and good will go together?
Thank you so much Venerable, a very helpful reply! 
Dear Bhante @Akaliko
Thank you, that was clear and easy to understand; I am grateful for the detail of your answer. Bookmarked for future reference.
Thank you for your input, it helped round-out and colour my understanding of Anger vs Ill-will.
With mettÄ
Michael
Bikkhu Bodhi makes the point in regard to the second link of the noble eightfold path that ill will does not necessarily result in immediate action, whereas cruelty (and anger) are likely to. So they are stages in a process from internal to external. Between good will and ill will there is non ill will. Good will and non ill will are meanings of metta.
It also might be helpful to consider that, on a basic limbic level, anger is a response to a perceived threat of danger and may be associated with a fight or flight response. Ill will is more of a conditioned decision.