destrier
Concise Oxford English Dictionary © 2008 Oxford University Press:
destrier /ˈdɛstrɪə, dɛˈstriːə/
▶noun a medieval knight's warhorse.
– origin ME: from OFr., based on L. dextera ‘the right hand’, from dexter ‘on the right’ (because the squire led the knight's horse with his right hand).
'destrier' also found in these Oxford entries:

