eructation
Concise Oxford English Dictionary © 2008 Oxford University Press:
eructation /ˌiːrʌkˈteɪʃ(ə)n, ɪ-, ɛ-/
▶noun formal a belch.
– origin ME: from L. eructatio(n-), from eructare, from e- (var. of ex-) ‘out’ + ructare ‘belch’.
'eructation' also found in these Oxford entries:

