demean
/dɪˈmi:n; dɪ`min/ v[Tn, Tnt]
~ oneself lower oneself in dignity; deprive oneself of others' respect 降低自己的身分; 失去别人的尊重; 贬低自己
Don't demean yourself by telling such obvious lies. 你不要用这种明显的谎言自贬人格.
I wouldn't demean myself to ask for favours from them. 我不会降低身分向他们求情.