To exert muscular energy, as against a material force or mass, To have difficulty or make a strenuous effort doing something, To move or place (something) with an effort, verb_ make a strenuous or labored effort, to exert strenuous effort against opposition, make a strenuous or labored effort, noun_ an energetic attempt to achieve something, an open clash between two opposing groups (or individuals), strife, contention, great effort