Etymology From duck (“aquatic bird”) + -y (diminutive suffix).
1
Childish A duck (aquatic bird), especially a toy rubber duck.
Do little things for your Inner Child, like taking bubble baths. Invite a rubber ducky to play with you...1990, Donna LeBlanc, You can't quit until you know what's eating you:
Dated, Slang Great; going well; proceeding in an eminently agreeable fashion.
Farnesworth smiled contentedly as he read the stock ticker; all was ducky on Wall Street.
1930, Mickey Mouse newspaper comic Isn't this the duckiest little leather skirt you ever saw?
1 more example
Fortunately, she had bragged to everybody about her ducky first-floor apartment in the perfectly darling three-story red-brick.1942, James Thurber, The Catbird Seat: