militate

/ˌmɪləˈteɪt/

Other forms: militated; militates; militating

Your father's loss of his job may militate against the big family vacation your parents had been planning. To militate is to be a deciding factor for or against.

The word militate descends from the same Latin word as military. Imagine armed soldiers at a check point. Their presence might militate against your plan of crossing the border, or it might militate for their bringing you in for questioning. When you are young, sometimes your age works for you, and sometimes it militates against you.

Definitions of militate

1. verb

   have force or influence; bring about an effect or change
   “Politeness militated against this opinion being expressed”

   type of:

   act upon, influence, work

   have and exert influence or effect