quarter-turn1
noun
A turn of 90°; this action or manoeuvre.
Origin
Mid 17th century.
quarter-turn2
verb
1 [with object] To turn through 90°, specifically to turn (a bell) 90° on its stock.
2 [no object] To make a quarter-turn.
Origin
Early 20th century; earliest use found in Sammelbände der Internationalen Musikgesellschaft.