An Etymological Dictionary of Astronomy and Astrophysics

1a) General: A driving movement or force; impulse; impetus; pressure.

1b) Physics: A slight change of a quantity with time, for example the sensitivity of an electronic detector continuously operated during a long period as an effect of continued use.

1c) A slow change in frequency of a radio transmitter.

1d) Aerospace: The gradual deviation of a rocket or guided missile from its intended trajectory.

2. (v.intr.) To be carried along by currents of water or air, or by the force of circumstances.

Etymology (EN): From M.E. drift, from O.E. drifan “to drive,” or from O.N. or M.Du. drift, from P.Gmc. *driftiz, related to *dribanan “to drive.”

Etymology (PE): Delek from Lori, Laki, Hamadâni, Malâyeri “push, shove, drive;” variants Gilaki duko, Tâleši dako, Baluchi dhakkk(a) “push, shove, blow,” Choresmian dh- “to hit,” Kurd. dân/di- “to beat, hit,” Proto-Iranian *daH- “to beat, hit, strike” (Cheung 2007); PIE base *dhen- “to hit, push;” delekidan, verb from delek.