a cheap ornament; trinket
an ornamental article of furniture, dress, etc

Derived Formsknick-knackery or nick-nackery, noun

Word Origin for knick-knack

C17: by reduplication from knack, in obsolete sense: toy
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

Examples from the Web for knick-knack

Historical Examples of knick-knack

Word Origin and History for knick-knack

also knickknack, 1570s, reduplication of knack "stratagem, trick."

Online Etymology Dictionary, © 2010 Douglas Harper