sǐ xīn tā dì
to be hell-bent on
dead set on sth
unswerving
sǐ xīn
to give up
to admit failure
to drop the matter
to reconcile oneself to loss
to have no more illusions about
bù sǐ xīn
unwilling to give up
unresigned
sǐ xīn yǎn r
stubborn
obstinate
having a one-track mind
sǐ xīn tà dì
see 死心塌地[si3 xin1 ta1 di4]