specialise vs flesh out

specialise and flesh out both are verbs.

Word	Noun	Adjective	Verb	Adverb
specialise	No	No	Yes	No
flesh out	No	No	Yes	No

As verbs, flesh out is a hypernym of specialise; that is, flesh out is a word with a broader meaning than specialise:

specialise: be specific about
flesh out: add details, as to an account or idea; clarify the meaning of and discourse in a learned way, usually in writing

Other hypernyms of specialise include dilate, elaborate, enlarge, expand, expatiate, exposit, expound, lucubrate.

specialise (verb)	flesh out (verb)
become more focused on an area of activity or field of study	become round, plump, or shapely
suit to a special purpose	add details, as to an account or idea; clarify the meaning of and discourse in a learned way, usually in writing
evolve so as to lead to a new species or develop in a way most suited to the environment	make fat or plump
be specific about
devote oneself to a special area of work