膝袒

xītǎn
to walk on one's knees and bare one's breast (a gesture of deepest apology)

CEDICT

袒露上身，跪地以膝蓋前進。

重編國語辭典

Entry Composition

=1 膝 xī old variant of 膝 xī
=1 膝 xī knee
=2 袒 tǎn to bare
=2 袒 tǎn old variant of 袒 tǎn