The Collaborative International Dictionary of English v.0.48:

Suds \Suds\, n. pl. [Akin to sodden, seethe. See Seethe.]
   Water impregnated with soap, esp. when worked up into bubbles
   and froth.
   [1913 Webster]

   In the suds, in turmoil or difficulty. [Colloq.] --Beau. &
      Fl.
      [1913 Webster]