a correctly spelled word that does not fit in the context where it is used because it is the result of a spelling error on a different word that was intended
an accidentally inappropriate (usually that means 'humorous') choice, omission, or alteration of words
an erroneous or humorous substitution of one word or phrase for another
a whole word that supplants an intended word
a word used incorrectly by an author for a humorous purpose
An attempt to use a difficult word and getting it wrong, usually with humorous consequences! Named after the character Mrs. Malaprop who was notorious for doing this in Sheridan's The Rivals.
A malapropism is an incorrect usage of a word by substituting a similar-sounding word with different meaning, usually with comic effect.