a force to be reckoned with

:  strength or energy exerted or brought to bear :  cause of motion or change :  active power

: used with a number to indicate the strength of the wind according to the Beaufort scale

:  moral or mental strength

:  to do violence to

:  rape

:  to compel by physical, moral, or intellectual means

:  count

:  estimate, compute

:  to determine by reference to a fixed basis