Where does “胸ぐらを掴む” come from?

胸ぐらを掴む (Japanese) comes from Japanese を, from Proto-Japonic wo — accusative marker; away from, off.

Ancestry of “胸ぐらを掴む”, step by step

胸ぐらを掴む traces back through two separate lines of ancestry.

via Japanese を

StepLanguageWordMeaning
1JapaneseをA case particle; A conjunctive particle, usually...
2Proto-Japonicwoaccusative marker; away from, off

via Japanese 掴む

StepLanguageWordMeaning
1Japanese掴むto grab
2Japanese束bundle, bunch, batch, sheaf, coil; handbreadth,...
Every word from Proto-Japonic wo →Every word from Japanese を →