fro
adv. placeadv. away or back from a place. You almost always use it with the word 'to' when describing something moving back and forth.
adv. away or back from a location. Used almost exclusively in the fixed idiomatic phrase 'to and fro' to describe oscillatory motion.
The children ran to and fro in the park.
The pendulum swung to and fro, marking each second with a rhythmic click.
The small boat tossed to and fro on the choppy waters of the bay as the storm clouds gathered on the horizon.
From Middle English fro, fra, from Old English fra (“from”), from Old Norse frá (“from”), from Proto-Germanic fram (“from”), from Proto-Indo-European promo- (“forth, forward”). Cognate with Scots frae (“fro, from”), Icelandic frá (“from”). More at from.
Clipping of afro.
Occurs almost exclusively in the fixed adverbial phrase 'to and fro'.
He walked fro and to.He walked to and fro.The phrase is a fixed binomial idiom; the order of the words cannot be reversed.