vault (n.1) Look up vault at Dictionary.com
"arched roof or ceiling," c.1300, vaute, from Old French voute "arch, vaulting, vaulted roof or chamber," from Vulgar Latin *volta, contraction of *volvita, noun use of fem. of *volvitus, alteration of Latin volutus "bowed, arched," past participle of volvere "to turn, turn around, roll" (see volvox). The -l- appeared in English c.1400, an etymological insertion in imitation of earlier forms (compare fault (n.)).
vault (v.1) Look up vault at Dictionary.com
"jump or leap over," especially by aid of the hands or a pole, 1530s, transitive (implied in vaulting); 1560s, intransitive, from Middle French volter "to gambol, leap," from Italian voltare "to turn," from Vulgar Latin *volvitare "to turn, leap," frequentative of Latin volvere "to turn, turn around, roll" (see volvox). Related: Vaulted; vaulting.
vault (n.2) Look up vault at Dictionary.com
"a leap," especially using the hands or a pole, 1570s, from vault (v.1).
vault (v.2) Look up vault at Dictionary.com
"to form with a vault or arched roof," late 14c., from Old French vaulter, volter, from voute "arch, vaulted roof" (see vault (n.1)). Related: Vaulted; vaulting.