aficionado[əˌfɪsjə'nα:dəʊ,-ˌfɪʃjə-]
noun(pluralaficionados) a person who is very knowledgeable and enthusiastic about a particular activity or subject.
Origin
C19 (denoting a devotee of bullfighting): from Sp., 'amateur', past participle ofaficioner'become fond of' used as a noun, based on L.affectio(n-)(see affection).
ThesaurusaficionadonounCONNOISSEUR, expert, authority, specialist, pundit; enthusiast, devotee;informalbuff, freak, nut, fiend, maniac, fanatic, addict.