cross someone up

cross (one) (up)

To defy, challenge, or frustrate one. Don't cross that guy if you want a job in publishing—he's a celebrated editor. Stephen has crossed me up so many times I just can't trust him anymore.See also: cross

cross up

1. To deceive or swindle someone. A noun or pronoun can be used between "cross" and "up." Don't cross up that guy if you want a job in publishing—he's a celebrated editor.2. To confuse or mix up one or more things. I must have crossed up the files—this paperwork doesn't belong in here.See also: cross, up

cross someone (up)

and cross up someone tv. to go against someone; to thwart someone. Don’t cross me up if you know what’s good for you. See also: cross, someone, up