u-turn

Short definition from Wiktionary

Noun

1. 1
   Alternative letter-case form of U-turn.
2. 2
   A turn in a vehicle carried out by driving in a semicircle in order to travel in the opposite direction.
3. 3
   A reversal of policy or opinion.

Verb

1. 1
   To turn a vehicle in a semicircle so as to face the opposite direction (∩)).
2. 2
   To shift from one opinion or decision to its opposite.