gnawing
adjective uk/ˈnɔː.ɪŋ/ us/ˈnɑː.ɪŋ/
折磨人的;令人苦恼的;使人痛苦的
continuously uncomfortable, worrying, or painful
I've had gnawing doubts about this project for some time. 一段时间以来，我对这个项目一直怀有重重疑虑。
After three days, we felt an agonizing, gnawing hunger. 三天后，我们开始感觉到饥饿的煎熬和折磨。