1
ruffian;villain;knave;thief;suspicious fellow
2
peculiar person;idiosyncratic person;stubborn fellow
3
tricky thing;something that is more than it seems
4
expert;master;highly skilled person
5
goblin;apparition;monster;ghost;phantom;spectre;specter
Other forms
くせ者 【くせもの】 · 癖者 【くせもの】 (rarely used kanji form) · 曲物 【くせもの】 (search-only kanji form)