malapropos

/ˌmælæprəˈpoʊ/

It would be malapropos to wear full clown makeup to your cousin's formal wedding. In other words, it wouldn't be appropriate.

Use the adjective malapropos to describe something that is awkwardly unsuitable for the situation or setting at hand. Telling jokes at a funeral or bringing your pet piglet to tea at the Queen's castle would both be highly malapropos. The word comes from the French phrase mal à propos, literally "badly for the purpose." As it's French, you don't pronounce the final s.

Definitions of malapropos

1. adverb

   at an inconvenient time
   “she answered malapropos”

   synonyms: inopportunely
2. adjective

   of an inappropriate or incorrectly applied nature
   synonyms:

   inappropriate

   not suitable for a particular occasion etc

   inapposite, out of place

   of an inappropriate or misapplied nature

   antonyms:

   apropos

   of an appropriate or pertinent nature

   appropriate

   suitable for a particular person, place, condition, etc.

   apposite, apt, pertinent

   being of striking appropriateness and pertinence