Just to confirm what others have said. Dictionaries often emphasize early texts, but they cover the full range of meanings. Even in early contexts, they very often simply cite the commentary.
Normally a word changes in an organic way, so this is useful. In this particular case, however, the change in meaning is inorganic. What I mean by that is that it is not because of a general language drift, or because of subtle aspects of the word itself. It was changed to make it fit into Abhidhamma.
One of the overriding priorities of early Abhidhamma was to take teachings from different contexts and classify them in relation. So all the different terms for wisdom, for example, are collected and identified.
This happens from a largely ontological perspective; that is, the Abhidhamma is concerned with what these things are. Now, in the case of wisdom, there are many words that reflect different aspects of the development of wisdom. There is the reflection on the teaching; the insight into impermanence, the reviewing of the process of meditation, the penetration to the four noble things. But the exact role and function of the different terms is not the priority of the Abhidhamma, instead it simply says these are the same, since they are all “wisdom”.
One of the most important analyses is the six senses. So we want to see how other teachings fit into them. But we are concerned only with what these things “are” in their essence, not in their context.
Then it appears that the group of four map somewhat over the group of six.
- “seen” = “eye”
- “heard” = “ear”
- nose
- tongue
- body
- “cognized” = “mind”
So it is inferred that muta must apply to what is smelled, tasted, and touched, even though it literally never has this meaning. In this way the Abhidhammists use their method to override the meaning of natural language, which illustrates the point I made above that words have meanings.
One of the reasons for making this error was that the Abhidhammists worked in a time when the knowledge of the Brahmanical texts was already fading in the Buddhist community. The Buddha clearly picked this set up from Yajnavalka et al, and used in a specific sense.
In the suttas, these are used primarily to describe the ways in which religious of spiritual teachings are learned. The “seen” is not the “eye”, it is the “vision” of a holy person. The “heard” is not the “ear”, it is hearing the teaching. the “thought” is not whatever random processes happen in your mind, it is philosophical reflections. “Cognized” is not just anything you’re aware of, it’s the consciousness of samadhi.
Jayatilleke first pointed this out, and he was right. Obviously they are general words and can be used in a wider sense. But the main purpose of this teaching is to identify the ways in which we learn the truth.
And that is, of course, why the nose, tongue, and body are omitted. It’s not just a short hand or abbreviation, it’s because we do not learn spiritual truths this way.