Is the word 'unpack' a valid grammatical term? [closed]

I have seen the word 'unpack' used to describe the analysing of syntax and semantic expressions.

The OED does not list this usage of the word 'unpack'.

Is this a valid technical term in the examination of language ?

If so, what exactly should it convey and when was it first used in this sense ?

Solution 1:

Try this definition.

unpack VERB
1.2 Analyse (something) into its component elements.
Lexico

It is not a technical term in the examination of language. It is a general term, widely used. (As noted by Hot Licks, a metaphor.)