An uphill battle is a struggle that is hard the whole way. Face an uphill battle, an uphill battle from the start.
It does not say the battle is lost, only that nothing about it will be easy. The picture is military, since attacking uphill is the worst position to be in.
1nounuphill battleA struggle that is hard the whole way.
“Keeping the ward open was an uphill battle for three years.”
uphill battle is a struggle.
Practised in Idioms