WordNet sense 1 ((followed by `to') applying exclusively to a given category or condition or locality):

unique

WordNet sense 2 (separate and distinct from others of the same group or category):

particular

WordNet sense 3 (unique or specific to a person or thing or category):

peculiar, special

WordNet sense 4 (having a specific function or scope):

limited

WordNet sense 5 (clearly and explicitly stated):

specified