transitive (reflexive). To exert oneself (to do something); to strive, endeavour; to do one's best. Obsolete.
reflexive and intransitive. To do one's utmost endeavour, strive. Obsolete.
transitive (reflexive). To try, strive, or endeavour to the utmost; to do one's best. Obsolete.
reflexive and intransitive. To strain, press forward, use effort. Also with on.