The Collaborative International Dictionary of English v.0.48:

Vault \Vault\ (v[add]lt), v. t. [imp. & p. p. Vaulted; p. pr.
   & vb. n. Vaulting.] [OE. vouten, OF. volter, vouter, F.
   vo[^u]ter. See Vault an arch.]
   [1913 Webster]
   1. To form with a vault, or to cover with a vault; to give
      the shape of an arch to; to arch; as, to vault a roof; to
      vault a passage to a court.
      [1913 Webster]

            The shady arch that vaulted the broad green alley.
                                                  --Sir W.
                                                  Scott.
      [1913 Webster]

   2. [See Vault, v. i.] To leap over; esp., to leap over by
      aid of the hands or a pole; as, to vault a fence.
      [1913 Webster]

            I will vault credit, and affect high pleasures.
                                                  --Webster
                                                  (1623).
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Vaulting \Vault"ing\, n.
   1. The act of constructing vaults; a vaulted construction.
      [1913 Webster]

   2. Act of one who vaults or leaps.
      [1913 Webster]

WordNet (r) 3.0 (2006):

vaulting
    adj 1: revealing excessive self-confidence; reaching for the
           heights; "vaulting ambition" [syn: overreaching,
           vaulting]
    n 1: (architecture) a vaulted structure; "arches and vaulting"
    2: a light leap by a horse in which both hind legs leave the
       ground before the forelegs come down [syn: curvet,
       vaulting]