I. -ˈmen(t)-sh(ə-)nə-bəl adjective
Date: 1837
: not fit or allowed to be mentioned or discussed : unspeakable
an unmentionable topic
II. noun
Date: 1823
: one that is not to be mentioned or discussed: as
a. plural : pant III,1
b. plural : underwear
I. -ˈmen(t)-sh(ə-)nə-bəl adjective
Date: 1837
: not fit or allowed to be mentioned or discussed : unspeakable
an unmentionable topic
II. noun
Date: 1823
: one that is not to be mentioned or discussed: as
a. plural : pant III,1
b. plural : underwear
Merriam-Webster's Collegiate English vocabulary. Энциклопедический словарь английского языка Merriam Webster. 2003