- foam or froth made by a detergent, especially soap, when stirred or rubbed in water, as by a brush used in shaving or by hands in washing.
- foam or froth formed in profuse sweating, as on a horse.
- Informal. a state of excitement, agitation, nervous tension, or the like: He was in a lather over my delay.
verb (used without object)
- to form a lather: a soap that lathers well.
- to become covered with lather, as a horse.
verb (used with object)
- to apply lather to; cover with lather: He lathered his face before shaving.
- Informal. to beat or whip.
- a worker who puts up laths.
- foam or froth formed by the action of soap or a detergent in water
- foam formed by other liquid, such as the sweat of a horse
- informal a state of agitation or excitement
- to coat or become coated with lather
- (intr) to form a lather
n.Old English lauþr “foam, washing soda,” from Proto-Germanic *lauþran (cf. Old Norse lauðr “washing soap, foam”), from PIE *loutro- (cf. Gaulish lautron, Old Irish loathar “bathing tub,” Greek louein “to bathe,” Latin lavere “to wash”), which is from root *leu(e)- “to wash” + instrumentative suffix *-tro-. The modern noun might be a 16c. redevelopment from the verb. Meaning “violent perspiration” (especially of horses) is from 1650s. Meaning “state of agitation” (such as induces sweating) is from 1839. v.Old English laþran, from Proto-Germanic *lauþrjan (cf. Old Norse leyðra “to clean, wash;” see lather (n.)). Related: Lathered; lathering. see in a lather.