-eroo

  1. a suffix that creates familiar, usually jocular variations of semantically more neutral nouns; normally added to monosyllabic bases, or merged with bases ending in -er: flopperoo; smackeroo; switcheroo.

Origin of -eroo

of unclear orig.; perhaps extracted from buckaroo, though this word appears to have been conformed to a preexisting suffix (or word), the stress and final tense vowel being otherwise unaccounted for
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018