to-and-fro

[too-uhn-froh]

adjective

1. back-and-forth.

   to-and-fro motion.

noun

plural

to-and-fros 

1. a continuous or regular movement backward and forward; an alternating movement, flux, flow, etc..

   the to-and-fro of the surf.

to and fro

adjective

1. back and forth

2. here and there

Other Word Forms

• toing and froing noun

Word History and Origins

Origin of to and fro¹

First recorded in 1820–30; adj. and noun use of adv. phrase to and (fro) ( def. 2 )

Idioms and Phrases

Back and forth, as in He was like a caged animal, pacing to and fro. Strictly speaking, to means “toward” and fro “away from,” but this idiom is used more vaguely in the sense of “moving alternately in different directions.” [First half of 1300s]