-acious
(-ˈeɪʃəs)
compd. suffix, forming adjs. meaning ‘given to, inclined to, abounding in’; f. L. -āci- (nom. -ax), adj. ending added chiefly to vb. stems (Fr. -ace) + -ous; as L. vīv-ere to live, vīvāci- lively (Fr. vivace), Eng. vivaci-ous; so mendacious, voracious, fallacious, capacious. Hence adv. in -aciously; ns. of quality in -acious-ness, -acity; vbs. in -acitate.