Argthtjtr

What is the term when, in writing, a word is incorrectly replaced by a similar sounding word?

I think this occurs more commonly with popular phrases where the writer has only heard the word being used in speech, and hasn't seen it in text.

Some examples:

• Things took a turn for the worst - where it should be worse
  


• These events are unpresidented - where it should be unprecedented
  

I think this is a different issue than misspelling, because the writer is unaware of the proper use of the word they have written, even if they have spelled it correctly.

The most relevant term I have seen is misword, but according to the Merriam-Webster, it is for a word that is "wrongly spoken" not written.

EDIT: This also includes words that are similar sounding, but not homophones.

EDIT2: Using the wrong word when writing, not in conversation

There are at least four term for the incorrect use of a similar sounding word when writing, each with somewhat overlapping application, depending on the exact situation.

oronym

A pair of phrases which are homophonic. Examples:

• "I scream" instead of "ice cream";


• "four candles" instead of "fork handles".

eggcorn

"An idiosyncratic substitution of a word or phrase for a word or words that sound similar or identical [which] introduces a meaning that is different from the original but plausible in the same context" [my emphasis]. Examples:

• "eggcorn" instead of "acorn" [hence the origin of the term];


• "old-timers' disease" instead of "Alzheimer's disease";


• "preying mantis" instead of "praying mantis";


• "for all intensive purposes" instead of "for all intents and
  purposes"; and my favourite...


• "mating name" instead of "maiden name".

mondegreen

"A mishearing or misinterpretation of a phrase as a result of near-homophony, in a way that gives it a new meaning." The subtle distinction between a mondegreen and an eggcorn is that an eggcorn is roughly consistent with the meaning of the original word/phrase, whereas a mondegreen gives a new meaning. Mondegreens are particularly associated with misheard song lyrics. Examples:

• "...and Lady Mondegreen" instead of ""...and laid him on the green"
  (lyrics of the 17th-century Scottish ballad "The Bonnie Earl o'
  Moray") [hence the origin of the term]


• "'Scuse me while I kiss this guy" instead of "'Scuse me while I kiss
  the sky" (from the song "Purple Haze" by The Jimi Hendrix Experience)


• "Jose, can you see by the donzerly light" instead of "O say can you
  see, by the dawn's early light" (from the US national anthem - two
  mondegreens in one line!)


• "wrapped up like a douche" instead of "revved up like a deuce" (from
  "Blinded by the Light" by Manfred Mann's Earth Band)


• "See that girl, watch her scream, kicking the dancing queen" instead
  of "See that girl, watch that scene, diggin' the dancing queen" (from
  the ABBA song "Dancing Queen")

malapropism

"The use of an incorrect word in place of a word with a similar sound, resulting in a nonsensical, sometimes humorous utterance" [my emphasis]. Examples:

• "Sure, if I reprehend any thing in this world it is the use of my
  oracular tongue, and a nice derangement of epitaphs!" instead of something like "Sure, if I apprehend anything in this
  world, it is the use of my vernacular tongue, and a nice arrangement
  of epithets" (Mrs. Malaprop in Sheridan's play The Rivals, Act 3
  Scene III) [hence the origin of the term];


• "Our watch, sir, have indeed comprehended two auspicious persons"
  instead of "apprehended two suspicious persons" (Shakespeare's Much
  Ado About Nothing, Act 3, Scene V);


• Former Australian Prime Minister Tony Abbott once claimed that no one
  "is the suppository of all wisdom" (instead of "repository").

I believe the word you're looking for is Malapropism.

From the linked Wikipedia page:

A malapropism (also called a malaprop or Dogberryism) is the use of an
incorrect word in place of a word with a similar sound, resulting in a
nonsensical, sometimes humorous utterance. An example is the statement
by baseball player Yogi Berra, "Texas has a lot of electrical votes",
rather than "electoral votes".[1] Malapropisms often occur as errors
in natural speech and are sometimes the subject of media attention,
especially when made by politicians or other prominent individuals.
Philosopher Donald Davidson has noted that malapropisms show the
complex process through which the brain translates thoughts into
language.

Humorous malapropisms are the type that attract the most attention and
commentary, but bland malapropisms are common in speech and writing.

...

The word "malapropism" (and its earlier variant "malaprop") comes
from a character named "Mrs. Malaprop" in Richard Brinsley Sheridan's
1775 play The Rivals.[2] Mrs. Malaprop frequently misspeaks (to comic
effect) by using words which don't have the meaning that she intends
but which sound similar to words that do. Sheridan presumably chose
her name in humorous reference to the word malapropos, an adjective or
adverb meaning "inappropriate" or "inappropriately", derived from the
French phrase mal à propos (literally "poorly placed"). According to
the Oxford English Dictionary, the first recorded use of "malapropos"
in English is from 1630,[3] and the first person known to have used
the word "malaprop" in the sense of "a speech error" is Lord Byron in
1814.[4]

The answer, I believe, is eggcorn.

Eggcorn is a word or phrase that results from a mishearing or misinterpretation
of another, an element of the original being substituted for one which
sounds very similar.