depreciate
/dɪˈpri:ʃɪeɪt; dɪ`priʃɪˌet/ v
1 [I] become less valuable 贬值
Shares in the company have depreciated. 该公司的股票已经贬值.
2 [Tn] state that (sth) is not valuable, important, etc; disparage 贬低; 轻视
Don't depreciate my efforts to help/what I have done. 不要轻视我为帮忙所付出的努力[我已做的事].