不得不[bù dé bù]

have no choice but to; be bound to; be obliged to do sth.; cannot but; have to; cannot choose but; can't do better than; can't help but; can't keep from; can not refrain from; compel; force sb. to do sth.; have no option but to:

have to plead guilty;

不得不低头认罪

As time is limited， I have to hurry.

时间有限， 我不得不赶紧。