The verb has 5 meanings:
Meaning #1:
devote oneself to a special area of work
Synonym: specialize
Meaning #2:
be specific about
Synonyms: specify, particularize, particularise, specialize
Meaning #3:
suit to a special purpose
Synonym: specialize
Meaning #4:
become more special
Synonyms: specialize, narrow, narrow down
Antonym: diversify (meaning #3)
Meaning #5:
evolve so as to lead to a new species or develop in a way most suited to the environment, of populations of plants and animals
Synonyms: speciate, differentiate, specialize
