a foam or froth formed when a detergent, e.g. soap, is agitated in water

foam or froth on a horse's skin from profuse sweating

informal an agitated or overwrought state

to form a lather or cause (soap) to form a lather

to rub (something) until a lather is produced

to spread lather over (something)

(+ with) to spread something with (a substance)

She lathered the bread with jam

informal to beat or defeat (somebody) soundly

to form a lather