Where does “teenie-bopper” come from?

teenie-bopper (English) comes from English bopper, from English -er, from Middle English -er, from Old French -er, from Latin -ārius, from Proto-Italic *-āzios — Forms relational adjectives to nouns (and rarely numerals).

Ancestry of “teenie-bopper”, step by step

teenie-bopper traces back through two separate lines of ancestry.

via English bopper

StepLanguageWordMeaning
1EnglishbopperA person who dances the bop
2English-erA person or thing that does an action indicated...
3Middle English-eragentive suffix; agent noun suffix
4Old French-erAlternative form of -ier, verbal suffix;...
5Latin-āriuser
6Proto-Italic*-āziosForms relational adjectives to nouns (and rarely numerals)

via English teen

StepLanguageWordMeaning
1EnglishteenA teenager; Of or having to do with teenagers;...
2Middle Englishtenen
3Old Englishtȳnanto slander, vex
4Proto-West Germanic*tūnijanto enclose, put a fence around
Every word from Proto-Italic *-āzios