quirk

Short definition from Wiktionary

Noun

1. 1
   An idiosyncrasy; a slight glitch, a mannerism; something unusual about the manner or style of something or someone.
2. 2
   An acute angle dividing a molding; a groove that runs lengthwise between the upper part of a molding and a soffit.
3. 3
   A quibble, evasion, or subterfuge.

Verb

1. 1
   To (cause to) move with a wry jerk.
2. 2
   To furnish with a quirk or channel.
3. 3
   To alter in a unique and unusual way.
4. 4
   To use verbal tricks or quibbles.
5. 5
   Alternative form of querk.

Proper noun

1. 1
   A surname.