Definition of "catchy"

catchy

/ˈkæt͡ʃi/

adjective
comparative catchier, superlative catchiest
1. (of a tune or phrase) Instantly appealing and memorable.
  Quotations
  The best of friends become the worst of enemies when Barney makes a hilarious attack ad where he viciously pummels a cardboard cut-out of Homer before special guest star Linda Ronstadt joins the fun to both continue the attack on the helpless Homer stand-in and croon a slanderously accurate, insanely catchy jingle about how “Mr. Plow is a loser/And I think he is a boozer.”
  2012 June 3, Nathan Rabin, “TV: Review: THE SIMPSONS (CLASSIC): “Mr. Plow” (season 4, episode 9; originally aired 11/19/1992)”, in (Please provide the book title or journal name)‎
2. (dated, chiefly figurative) Tending to catch or ensnare; entangling.
3. (dated) Consisting of, or occurring in, disconnected parts or snatches; changeable.
  Quotations
  It [the fox's scent] is […] flighty or catchy, if variable.
  Encyc. of Sport
4. Contagious; catching.
  Quotations
  The catchy cold which has been transmitted to you directly or indirectly might have been avoided had you been in better physical condition.
  1941, Florence LaGanke Harris, Hazel Hanna Huston, The New Home Economics Omnibus