n. & v.
--n.
1. a froth produced by agitating soap etc. and water.
2 frothy sweat, esp. of a horse.
3 a state of agitation.
--v.
1. intr. (of soap etc.) form a lather.
2 tr. cover with lather.
3 intr. (of a horse etc.) develop or become covered with lather.
4 tr. colloq. thrash.
Derivatives:
lathery adj.
Etymology: OE leathor (n.), lethran (v.)