The Collaborative International Dictionary of English v.0.48:

Noctambulation \Noc*tam`bu*la"tion\, n. [L. nox, noctis, night +
   ambulare to walk: cf. F. noctambulation.]
   Somnambulism; sleepwalking; walking in one's sleep. --Quain.
   [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

noctambulation
    n 1: walking by a person who is asleep [syn: sleepwalking,
         somnambulism, somnambulation, noctambulism,
         noctambulation]