gnaw
/nɔ:; nɔ/ v
1 [Ipr, Tn] ~ (at) sth bite sth hard continually until it is worn away 不断地啃, 咬, 啮硬物（直至啃掉、 咬去、 啮断）
a dog gnawing (at) a bone 啃著骨头的狗
a boy gnawing his fingernails 咬著指甲的男孩.
2 [Ipr, Ip, Tn]
~ (at) sb/sth (fig 比喻) cause sb/sth continual distress and torment 使某人苦恼; 使某事物受折磨
fear and anxiety gnawing (at) one's heart 心中受著恐惧和不安的折磨
the gnawing pains of hunger 饥饿引起的绞痛
guilt gnawing (away) at one's conscience 使良心不安的罪愆.
3 (phr v) gnaw sth away/off destroy sth gradually by gnawing 啃掉或咬坏某物
Rats gnawed off the lid of the box. 老鼠啃坏了箱盖.