Though not in the best of physical form, he was capable of moving with celerity.
-- Malachy McCourt, A Monk Swimming: A Memoir
Furthermore, as is well known, computer technology grows obsolete with amazing celerity.
-- Alan S. Blinder and Richard E. Quandt, "The Computer and the Economy", The Atlantic, December 1997
The lightning celerity of his thought processes took you on a kind of helter-skelter ride of surreal non-sequiturs, sudden accesses of emotion and ribald asides, made all the more bizarre for being uttered in those honeyed tones by the impeccably elegant gent before you.
-- "A life full of frolics", The Guardian, May 19, 2001
Celerity is from Latin celeritas, from celer, "swift." It is related to accelerate.