from ἰσχύς; to have (or exercise) force (literally or figuratively):--be able, avail, can do(-not), could, be good, might, prevail, be of strength, be whole, + much work.
akin to the base of κελεύω; to "call" (properly, aloud, but used in a variety of applications, directly or otherwise):--bid, call (forth), (whose, whose sur-)name (was (called)).