What is the meaning of lather?

noun

• The froth produced by soaps or detergents.
  • synonyms: soapsuds, suds
• Agitation resulting from active worry.
  • usage: "don't get in a stew"; "he's in a sweat about exams"
  • synonyms: fret, stew, sweat, swither
• A workman who puts up laths.
• The foam resulting from excessive sweating (as on a horse. )

verb

• Beat severely with a whip or rod.
  • usage: "The teacher often flogged the students"; "The children were severely trounced"
  • synonyms: flog, welt, whip, lash, slash, strap, trounce
• Form a lather.
  • usage: "The shaving cream lathered"
• Exude sweat or lather.
  • usage: "this unfit horse lathers easily"
• Rub soap all over, usually with the purpose of cleaning.
  • synonyms: soap