'Exert' definitions:

Definition of 'exert'

verb

Put to use; "exert one's power or influence" [syn: exert, exercise]

verb

Have and exercise; "wield power and authority" [syn: wield, exert, maintain]

verb

Make a great effort at a mental or physical task; "exert oneself"

From: GCIDE

Exert \Ex*ert"\, v. t. [imp. & p. p. Exerted; p. pr. & vb. n. Exerting.] [L. exertus, exsertus, p. p. of exerere, exserere, to thrust out; ex out + serere to join or bind together. See Series, and cf. Exsert.]
1. To thrust forth; to emit; to push out. [Obs.] [1913 Webster]
So from the seas exerts his radiant head The star by whom the lights of heaven are led. --Dryden. [1913 Webster]
2. To put force, ability, or anything of the nature of an active faculty; to put in vigorous action; to bring into active operation; as, to exert the strength of the body, limbs, faculties, or imagination; to exert the mind or the voice. [1913 Webster]
3. To put forth, as the result or exercise of effort; to bring to bear; to do or perform. [1913 Webster]
When we will has exerted an act of command on any faculty of the soul or member of the body. --South. [1913 Webster]
To exert one's self, to use efforts or endeavors; to strive; to make an attempt. [1913 Webster]