The term “straight-up” is used to describe a team that wins the game or to describe a bet on a team to win the game.
To win a bet “straight-up” you are looking to wager on the moneyline, which is a bet just to win a game outright, regardless of the spread.
For example, if you wanted to place a bet on the Golden State Warriors to win a game regardless of point spread, you would be looking for the Warriors to win “straight-up.”
Or for example, if you are looking to place a bet on the Warriors to win the game, you would be interested in placing a bet on the money line.
Either way, you are interesting is betting a team just to win a particular game, regardless of the point spread handicap.