Meaning of “lather” - Learner’s Dictionary

lather

noun uk us /ˈlɑːðər/

[ U ] small white bubbles that are produced when soap is used with water

get into a lather informal

to become anxious or upset about something:

She'd got into a lather over the arrangements for the party.

(Definition of “lather” from the Cambridge Learner’s Dictionary © Cambridge University Press)