smarty-pants

[ smahr-tee-pants ]
/ ˈsmɑr tiˌpænts /

noun (used with a singular verb)

Origin of smarty-pants

First recorded in 1915–20
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for smarty-pants

smarty-pants

smarty-boots (ˈsmɑːtɪˌbuːts)

/ (ˈsmɑːtɪˌpænts) /

noun

(functioning as singular) informal a would-be clever person
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012