[vault] n [ME voute, fr. MF, fr. (assumed) VL volvita turn, vault, fr. fem. of volvitus, alter. of L volutus, pp. of volvere to roll--more at voluble] (14c) 1 a: an arched structure of masonry usu. forming a ceiling or roof b: something (as the sky) resembling a vault c: an arched or dome-shaped anatomical structure
2. a: a space covered by an arched structure; esp: an underground passage or room b: an underground storage compartment c: a room or compartment for the safekeeping of valuables 3 a: a burial chamber b: a prefabricated container usu. of metal or concrete into which a casket is placed at burial -- vaulty adj
[2]vault vt (14c): to form or cover with or as if with a vault: arch [3]vault vb [MF volter, fr. OIt voltare, fr. (assumed) VL volvitare to turn, leap, freq. of L volvere] vi (1538) 1: to bound vigorously; esp: to execute a leap using the hands or a pole
2: to do or achieve something as if by a leap ~ vt: to leap over; esp: to leap over by or as if by aid of the hands or a pole [4]vault n (1576): an act of vaulting: leap