unmentionables

UK: /ʌnˈmɛnʃənəb^əlz/

Collins Concise English Dictionary © HarperCollins Publishers::

unmentionables / ʌnˈmɛnʃənəb^əlz/ noun:plural

1. underwear

WordReference Random House Learner's Dictionary of American English © 2025

un•men•tion•a•ble /ʌnˈmɛnʃənəbəl/   adj. 

1. not appropriate, unfit, or improper to be mentioned or spoken about:
   an unmentionable subject.

n. [countable]

2. something that is not to be mentioned.
3. Clothing unmentionables, [plural] undergarments.

WordReference Random House Unabridged Dictionary of American English © 2025

un•men•tion•a•ble  (un men′shə nə bəl), adj. 

1. not mentionable;
   inappropriate, unfit, or improper for mention, as in polite conversation;
   unspeakable.

n. 

2. something that is not to be mentioned:
   That subject was classed among the unmentionables.
3. Clothing unmentionables:
   • undergarments.
   • (formerly) trousers or breeches.

• un-¹ + mentionable 1820–30

un•men′tion•a•ble•ness, n.