The Austronesian Comparative Dictionary

*buR(e)túŋ only child; alone, by onself; go it alone

PPh buR(e)túŋ only child; alone, by onself; go it alone

WMP
Bontok bugtúŋ an only child; a single offspring in a delivery, of animals that normally have litters
Ifugaw bugtuŋ an only child of a man, a woman
Kankanaey ma-bugtóŋ (to carry, etc.) alone, by one’s self
Ifugaw (Batad) bugtuŋ an only child of a man, a woman
Ibaloy on-boltoŋ to separate oneself, go on one’s own (as a goat that leaves the herd, young married couple who leave their parents and set up their own home, person who goes into business for himself
Pangasinan bogtóŋ only (in the sense of ‘none other’; applied to offspring of people, plants or animals)
Ilokano bugtóŋ one of its kind
bug-bugtóŋ only, sole, single; unique
Ayta Abellan bogtoŋ the only one
Tagalog bugtóŋ lone; the only one; sole (as an only child)
Hanunóo bugtúŋ one and only, truly unique
Aklanon búgtoŋ only child
Agutaynen bogtoŋ only offspring of a human or animal
Cebuano bugtúŋ sole, lone
b<in>ugtuŋ to do s.t. alone, single-handedly; to do s.t. with another in singles
Binukid bugtuŋ sole, lone, only
Maranao boto-botoŋ one, the only (as in an only child)
Mansaka bogtoŋ only one; only begotten; sole; lone
Bikol bugtóŋ the only child in a family