ascus
Concise Oxford English Dictionary © 2008 Oxford University Press:
ascus /ˈaskəs/
▶noun (pl. asci /ˈaskʌɪ, -iː/) Botany a sac in which the spores of ascomycete fungi develop.
– origin C19: mod. L., from Gk askos ‘bag’.
'ascus' also found in these Oxford entries:

