From Wiktionary, the free dictionary
Backslang from boso + -ing.
usbíng (Baybayin spelling ᜂᜐ᜔ᜊᜒᜅ᜔)
- (slang) peeping tom; peep
- Synonyms: maninilip, mamboboso, bosero
- Zorc, R. David, San Miguel, Rachel (1993) Tagalog Slang Dictionary, Manila: De La Salle University Press, →ISBN, page 151