unmentionable

unmentionable — adjective

1. too shocking, embarrassing, or offensive to be spoken about openly, especially b

1.adjectiveC1
Definition

too shocking, embarrassing, or offensive to be spoken about openly, especially because it would break the rules of polite behaviour or social convention

Example

During the formal dinner, Stefan avoided any unmentionable topics like politics or religion.

attributive: unmentionable + [topic/subject/noun]

The family kept their financial troubles as an unmentionable secret for many years.

collocation: unmentionable secret

Common collocations
  • unmentionable subject
  • unmentionable topic
  • unmentionable secret
  • unmentionable issue
  • unmentionable problem
Synonyms
  • taboo

    broader; describes any subject forbidden by social or religious custom, not necessarily shocking

  • unspeakable

    stronger; suggests extreme horror rather than social embarrassment

  • forbidden

    broader; can refer to any prohibited thing, not just topics of conversation

Antonyms
  • mentionable

    rare; describes something acceptable to discuss openly

Grammar Patterns

unmentionable + noun

Usage Note

Commonly used attributively before nouns such as 'subject', 'topic', 'secret', 'issue', or 'problem'. Rarely used in comparative or superlative forms.

Common Mistakes

He talked about an unmentionable' (as a countable noun for a shocking topic).
He brought up an unmentionable subject.
for the 'too shocking to discuss' meaning, unmentionable is normally an adjective before a noun, not a standalone noun.

unmentionable — noun

Word family

Synonym discussion

Sense: adjective/1

All four words describe things that are not permitted or acceptable in conversation, but they differ in intensity and scope. 'Unmentionable' is the mildest and most socially focused — it refers to topics that polite convention excludes from conversation (e.g. 'unmentionable financial troubles'). 'Taboo' is broader, covering actions, words, and subjects forbidden by religious, cultural, or social rules, whether shocking or not (e.g. 'taboo to eat certain foods'). 'Unspeakable' is much stronger and suggests horror, cruelty, or trauma so severe that language itself fails (e.g. 'unspeakable acts of violence'). 'Forbidden' is the most general term for anything prohibited by authority, law, or rule, without the embarrassment or social-discomfort dimension. When choosing between them, consider whether the emphasis is on social awkwardness (unmentionable), cultural prohibition (taboo), horror (unspeakable), or rule-breaking (forbidden).

unmentionable ↗taboounspeakableforbidden ↗

Common collocations

Nouns

Adverbs

Phrases

  • treated as unmentionable
  • considered unmentionable
  • remain unmentionable

Etymology

English (un- + mention + -able)Latin (mentio)English

Formed in English by adding the suffix -able to the verb 'mention', with the negative prefix un-. The word first appeared in print in the early 1830s during the Victorian era, when strict rules of polite conversation made many everyday words improper. The noun form 'unmentionables' (initially referring to trousers) arose around 1835 as a humorous euphemism, later shifting to mean underwear by the late 1800s. The adjective sense (a topic too shocking to discuss) developed alongside the noun.