wackadoodle /ˈwækəˌdudəl/adjective 1noun 1forms 3 adjective1 •(slang, disapproving) Crazy, irrational, or eccentric.I thought that was totally wackadoodle. How could they possibly love someone they've never met? — 2010 noun1 •(slang, disapproving) A crazy, irrational, or eccentric person."It's not funny, Mom! I use that mitt all the time. What kind of wackadoodle poops in her sister's baseball glove, for crying out loud?" — 2013 formswackadoodles · more wackadoodle · most wackadoodle