ducky (adj.)

"excellent," slang from 1897 (often ironical),perhaps from duckie as a term of endearment (by 1853). Rev. Palmer ["Folk-Etymology," 1882] finds the use of duck as a term of endearment "identical with Danish dukke, a baby or puppet (Wolff), Ger. docke, a doll or puppet, Shetland duckie, a doll or little girl ...," and thinks it probably is not a metaphoric use of the water-bird word, or related to the much earlier slang or dialectal noun meaning "a woman's breast" ["...whose pritty duckys I trust shortly to kysse," Henry VIII, c. 1536 letter to Anne Boleyn, who, contrary to historical rumor, did not have three of them], which perhaps is from dug (n.).