say it: SPESH-uh-luhst
specialist is a noun meaning "an expert who is devoted to one occupation or branch of learning". It carries 2 recorded senses.
an expert who is devoted to one occupation or branch of learning
practices one branch of medicine
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for specialist come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.