The Austronesian Comparative Dictionary

*bug(e)túŋ alone, single

PPh bug(e)túŋ alone, single

WMP
Bontok bugtúŋ an only child; a single offspring in a delivery, of animals that normally have litters
Ifugaw búttoŋ firstborn child; a first born child which is the only one
Kankanaey ma-bugtóŋ to carry, etc. alone, by oneself
Ayta Abellan bogtoŋ single; only one
Tagalog bugtóŋ lone; the only one; sole
Hanunóo bugtúŋ one and only, truly unique
Binukid bugtuŋ sole, lone, only
Maranao botoŋ alone, lone, one, single