underdog

US /ˈʌn.dɚ.dɑːɡ/
UK /ˈʌn.dɚ.dɑːɡ/
"underdog" picture
1.

a competitor thought to have little chance of winning a fight or contest

:
The team was the underdog, but they managed to win the championship.
Everyone loves to root for the underdog.
2.

a person who is expected to lose or fail in a competition or struggle

:
Despite being the underdog, she never gave up hope.
The small startup was the underdog against the giant corporation.