spe ‧ cial ‧ ist S3 W3 /ˈspeʃ ə ləst, ˈspeʃ ə lɪst/ BrE AmE noun [countable]
[ Word Family: noun : ↑ special , ↑ specialist , SPECIALITY/SPECIALTY , ↑ specialization , ↑ specialism ; adjective : ↑ special , ↑ specialized ; verb : ↑ specialize ; adverb : ↑ specially ]
1 . someone who knows a lot about a particular subject, or is very skilled at it SYN expert
specialist in
an attorney who is a specialist in banking law
2 . a doctor who knows more about one particular type of illness or treatment than other doctors:
a heart specialist