Exertion is the use of physical or mental ENERGY to accomplish a task. Crossword solutions for the term exertion include ATTEMPT (7 letters), ACTIVITY (8 letters), EMPLOYMENT (10 letters), APPLICATION (11 letters), STRIVING (8 letters), TRAVAIL (7 letters), FORCE (5 letters), ESSAY (5 letters), work (4 letters), PAINS (5 letters), EXERCISE (8 letters), TRIAL (5 letters), ACTION (6 letters), TROUBLE (7 letters), ENERGY (6 letters), TOIL (4 letters), DINT (4 letters), SWEAT (5 letters), STRAIN (6 letters), EFFORT (6 letters), nisus (5 letters), and elbowgrease (11 letters). All of these words refer to the use of physical or mental ENERGY to accomplish a task, which is the definition of exertion.