Gents what CAP (or EASA equivalent) does the civil world use to define Engineering Terminology, in order that any engineer writing up his paper work won’t fall foul of the law.
There are also definitions sections in the front of each of the new EASA Certification Specifications, so if you have a rummage around here you'll find specific stuff for e.g. engines, propellers...
None of which are brilliant, and to be honest there are several unofficial technical dictionaries which are probably more useful (and a lot more readable!)