cock-up

Short definition from Wiktionary

Noun

1. 1
   A mistake.
2. 2
   A superior letter; a lower-case letter placed above the baseline and made smaller than ordinary script; traditionally used in abbreviations.
3. 3
   A roll or twist of hair worn at the nape of the neck; a bun.

Verb

1. 1
   To ruin (something) unintentionally; to fuck up, mess up, or screw up.