A source or object of fear, especially of unnecessary fear; a bugbear.
Origin
Mid 16th century; earliest use found in William Patten (d.?1598), author. From classical Latin terriculāmentum object of terror, bugbear (2nd cent. a.d. in Apuleius) from terriculum (also terricula) something that excites terror (from terrēre to frighten + -culum (or -cula)) + -mentum.