Mao Collection, Upper Volume
Radical: Heart (xīn)
忝
Kangxi strokes: 8
Page 377, Entry 08
Tang Rhymes (Tangyun), Collected Rhymes (Jiyun), Dictionary of Rhymes (Yunhui), and Correct Rhymes (Zhengyun): pronounced tian (rising tone).
Shuowen Jiezi: to disgrace.
Book of Documents (Shangshu), Canon of Yao: if my virtue disgraces the imperial throne.
Book of Odes (Shijing), Lesser Odes: do not disgrace those who gave you life.
Also, Guangyun, Collected Rhymes (Jiyun), Dictionary of Rhymes (Yunhui), and Correct Rhymes (Zhengyun): pronounced tian (falling tone). Same meaning.