便了biànliǎo〈助词aux.〉用在句末,表示决定、允诺或让步的语气,跟‘就是了’相同(多见于早期白话{oft. in early vernacular}){[used at the end of a sentence to indicate determination, promise or concession] same as the meaning of 就是了 jiùshì·le}: 如有差池,由我担待～。{I will be responsible for any mistake; you can be sure.}