mar-all

From mar +‎ all. See mar (“to spoil”).

• (General American) IPA^(key): /mɑɹ.ɑl/

mar-all (plural mar-alls)

1. (obsolete, idiomatic) A spoilsport, an addle-plot.
   • 1623, William Shakespeare, “Act 5 Scene 1”, in Macbeth, etc.:

     You mar all with this starting.

• (something or someone who spoils an enjoyable event): dampener, killjoy, wet blanket, (person), party-pooper (person); see also Thesaurus:spoilsport