Hippocrene
Concise Oxford English Dictionary © 2008 Oxford University Press:
Hippocrene /ˈhɪpəkriːn/
▶noun literary poetic or literary inspiration.
– origin C17: via L. from Gk Hippokrēnē, Hippou krēnē, lit. ‘fountain of the horse’, the name of a fountain on Mount Helicon sacred to the Muses, which according to legend was produced by a stroke of Pegasus' hoof.
'Hippocrene' also found in these Oxford entries:

