The Collaborative International Dictionary of English v.0.48:

Yuck \Yuck\, v. i. [Cf. G. jucken, D. yeuken, joken. See
   Itch.]
   To itch. [Prov. Eng.] --Grose.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Yuck \Yuck\, v. t.
   To scratch. [Prov. Eng.] --Wright.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

yuck \yuck\, interj.
   an interjection expressing repugnance or distaste.
   [PJC]

The Collaborative International Dictionary of English v.0.48:

yuck \yuck\ n.
   a laugh; also, a joke or gag; -- usually used in the plural,
   as, the skit got lots of yucks. [slang]

   Syn: laugh; gag; joke
        [PJC]