dirk

Short definition from Wiktionary

Noun

1. 1
   A long Scottish dagger with a straight blade.
2. 2
   A ceremonial dagger worn by naval or air force officers in some nations' militaries; formerly, a fighting dagger used by sailors as a boarding weapon.
3. 3
   A penis.
4. 4
   A socially unacceptable person; an oddball.

Verb

1. 1
   To stab with a dirk.
2. 2
   To darken.

Proper noun

1. 1
   A male given name from German or Dutch, equivalent to English Derek.
2. 2
   A surname transferred from the given name.