endeavour (subs.) Copy link • endeavour (subs.): cōnātus, ūs; cōnātum (esp. in pl.): v. attempt. Phr.: to use one's utmost e.s, dare operam ut (ne), Sall.: Cic.: I must use my utmost e.s, omnibus nervis mihi contendendum est, Cic. Verr. 3, 56, 130; simly, omnes nervos aetatis industriaeque contendere, ib. 1, 12, 35. See also effort.