Definition of oustiti in English:

oustiti

Pronunciation /ˈuːstɪti/

noun

slang
  • A tool inserted into a keyhole from the side opposite the key so as to grasp and turn the key.

Origin

1940s; earliest use found in Georgette Heyer (1902–1974), novelist. Irregularly from French ouistiti, perhaps a humorous specific use of ouistiti.