D defs.my
Entry 1 sense Webster, 1913

Twelfth-second

· Twelfth·-sec·ond · IPA
01 n. A unit for the measurement of small intervals of time, such that 1012 (ten trillion) of these units make one second.
  1. 1.
    A unit for the measurement of small intervals of time, such that 1012 (ten trillion) of these units make one second.(Physics)