0 a person or group of people with less power, money, etc. than the rest of society -- los desamparados, los grupos menos favorecidos
As a politician, her sympathy was always for the underdog in society.
1 a weak person who is dominated by someone else, or who is the loser in a struggle -- desfavorecido; desvalido; desamparado
He always likes to help the underdog.
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.
Podemos completarlo paso a paso, por muy largo que sea el camino, y no se puede completar, por corto que sea el camino, si ni siquiera marcas tu huella.