the use in inflection or derivation of an allomorph that is not related in form to the primary allomorph of a morpheme, as the use of better as the comparative of good.
Origin of suppletion
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
the use of an unrelated word to complete the otherwise defective paradigm of a given word, as for example the use of went for the past tense of go
Word Origin for suppletion
C14: from Medieval Latin supplētiō a completing, from Latin supplēre to supply 1
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