köken: From Proto-Malayo-Polynesian *təʀas (cf. Central Bikol tagas, Cebuano tugas (“molave”), Ibanag nategga (“hard”), Kapampangan siyas (“hard”), Indonesian teras and Malay teras (“heart of wood”), Maranao tegas).
aile: antigas, astig, itigas, katigasan, katigasan ng katawan, katigasan ng loob, katigasan ng ulo, maastigan, magmatigas, magmatigas ng puso