undersell  
verb [ T ] uk/ˌʌn.dəˈsel/ us/ˌʌn.dɚˈsel/ undersold | undersold
  (SELL CHEAPLY)      
  以低于(竞争对手)的价格出售
to sell goods at a price lower than a competitor
  A big supermarket can usually undersell a small local store. 大型超市的售价常常可以低于当地的小店铺。 
   (BE MODEST)      
 贬损(尤指自己)
to not give something or someone, especially yourself, the praise that is deserved
  Don't undersell yourself - you have a lot to offer a company. 不要妄自菲薄——你有很多东西可以贡献公司。