1. have/put (someone) in a difficult situation or at your mercy
my boss has me over a barrel because he/she knows I need the work
The idiom to 'have someone over a barrel' means to have someone in a position where you can influence them to do what you want because you have given them very little choice or limited options. This phrase is often used in relation to a financial situation. similar in meaning to 'have someone on the ropes' or to be 'between a rock and a hard place'. To be 'over a barrel' means to be in a position where you are vulnerable or can be taken advantage of.