pò bù dé yǐ
to have no alternative (idiom); compelled by circumstances
forced into sth
bù dé yǐ
to act against one's will
to have no alternative but to
to have to
to have no choice
must
wàn bù dé yǐ
only when absolutely essential (idiom); as a last resort
bù dé yǐ ér wéi zhī
to have no other choice
to be the last resort