• 斥しりぞける — to repel; to reject; to drive away
• 排斥はいせき — exclusion; boycotting; rejection
• 斥力せきりょく — repulsive force
• 斥候せっこう — scout; reconnaissance (lit.)

The radical 斤 is an axe — a tool that chops things off. 斥 keeps that image of “cutting away,” giving the sense of pushing something back or refusing it.