The Collaborative International Dictionary of English v.0.48:

Apnoea \Ap*n[oe]"a\, n. [NL., fr. Gr. 'a priv. + ?, ?, breath, ?
   to breathe, blow.] (Med.)
   Partial privation or suspension of breath; suffocation; same
   as apnea.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

apnea \apnea\ n.
   1. transient cessation of respiration. [Also spelled
      apnoea.]
      [WordNet 1.5]

WordNet (r) 3.0 (2006):

apnea
    n 1: transient cessation of respiration