Pushover
/ˈpʊʃəʊvər/
Definition 1 of 2
Pro Tip 1/3Subtle Pressure
Used when someone gives in to pressure without much resistance. 
She agreed to work on her day off again, the team sees her as a pushover.
Pro Tip 2/3Negative Connotation
Often implies weakness or lack of assertiveness. 
He can't say no to extra work; he's known as the office pushover.
Pro Tip 3/3Manipulability
Highlights the ease at which a person can be manipulated. 
During debates, her pushover nature means her points are often dismissed.