succubus
Concise Oxford English Dictionary © 2008 Oxford University Press:
succubus /ˈsʌkjʊbəs/
▶noun (pl. succubi /-bʌɪ/) a female demon believed to have sexual intercourse with sleeping men.
– origin ME: from med. L. succubus ‘prostitute’, from succubare, from sub- ‘under’ + cubare ‘to lie’.
'succubus' also found in these Oxford entries:

