S: (v) specialize, specialise, narrow, narrow down (become more focused on an area of activity or field of study) "She specializes in Near Eastern history"
S: (adj) narrow-minded, narrow (lacking tolerance or flexibility or breadth of view) "a brilliant but narrow-minded judge"; "narrow opinions"
S: (adj) narrow (very limited in degree) "won by a narrow margin"; "a narrow escape"
S: (adj) minute, narrow (characterized by painstaking care and detailed examination) "a minute inspection of the grounds"; "a narrow scrutiny"; "an exact and minute report"