hypotenuse
Concise Oxford English Dictionary © 2008 Oxford University Press:
hypotenuse /hʌɪˈpɒtənjuːz, -s/
▶noun the longest side of a right-angled triangle, opposite the right angle.
– origin C16: via L. hypotenusa from Gk hupoteinousa (grammē) ‘subtending (line)’, from hupo ‘under’ + teinein ‘stretch’.
'hypotenuse' also found in these Oxford entries:
