underdog
noun uk/ˈʌn.də.dɒɡ/ us/ˈʌn.dɚ.dɑːɡ/
the underdog[ S ] 弱者；弱势群体
a person or group of people with less power, money, etc. than the rest of society
As a politician, her sympathy was always for the underdog in society. 作为一名政治家，她一直同情社会上的弱势群体。
[ C usually singular ]（比赛中）不被看好的一方
in a competition, the person or team considered to be the weakest and the least likely to win