Other forms: lathers
Lather is the foam soap makes when rubbed with water. Work up a lather, a rich lather, rinse off the lather.
The foam is not what cleans — the surfactant does that whether it foams or not — but people distrust a soap that will not lather, so manufacturers add foaming agents. A horse in a lather is covered in sweat foam. In a lather means agitated: he got into a lather about it. Note that the word is Old English and related to the Greek for a bath.
1nounlatherThe foam soap makes when rubbed with water.
“Rub the soap between your hands until you have a thick lather.”
2nounstateA state of agitation.
“Don't get into a lather about the party; everything is ready.”
lather is a foam, or an agitation.
Old English leathor meant washing soda, from a Proto-Indo-European root about washing. The Greek loutron, a bath, comes from the same root.
Proto-Indo-European
*lówh₃trom — that which is used for washing
Proto-Germanic
*lauþrą — that which is used for washing, soap
Proto-West Germanic
*lauþr
Old English
lēaþor — a kind of nitre used for soap, soda
Middle English
lather
English, today
lather
Built from
From Middle English lather, from Old English lēaþor (“a kind of nitre used for soap, soda”), from Proto-West Germanic lauþr, from Proto-Germanic lauþrą (“that which is used for washing, soap”), from Proto-Indo-European lówh₃trom (“that which is used for washing”), from lewh₃-, lowh₃- (“to wash, bathe”). Cognate with Swedish lödder (“lather, foam, froth, soap”), Icelandic löður (“foam, froth, a kind of niter used for soap”), Old Irish loathar (“wash-basin”), Ancient Greek λουτρόν (“a bath, wash-room”), Latin lavō (“to wash”), Albanian laj (“to wash”), Ancient Greek λούω. More at lye. Compare typologically мы́ло (a nomen instrumenti of мыть).
Etymology from Wiktionary, CC BY-SA
Practised in Hair & Grooming