-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 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
Slang definitions & phrases for -eroo

-eroo

suffix

used to form nouns (also -aroo or -roo or -oo) Emphatic, humorous, or affectionate form of what is indicated: babyroo/ floperoo/ jivaroo/ screameroo/ sockeroo (1930s+)