Plain English Meaning
How hard you are pushing the yoke or stick sideways to make the airplane bank, or to keep it from banking when something is trying to roll it.
Full Definition
The force the pilot applies to the control yoke or stick in the left or right direction to deflect the ailerons and produce or correct a roll about the longitudinal axis. It is the sensed resistance of the controls when commanding bank, and is adjusted continuously to hold a desired bank angle or to roll into and out of turns.