1. The unintentional and incorrect spelling of a desired word, or indeed putting the WRONG word instead.

2. A funky word for typos.

3. A chronic illness that prevents the correct spelling of words. (Not to be confused with dyslexia)

(*Typoretardism usually occurs when a person tries to type in darkness, misplaces fingers on a keyboard or thinks faster than they type and write the wrong word.)
Example 1-

Leah: Lily Allen and Country Love were fighting on Twitter
Jamie: Country? you mean Courtney XD
Leah: LOL XD
Jamie: Typoretardism

Example 2-

Jamie: Makes England look comparitively DRY
Jamie: mind you England is still like 50% of the worlds wettets
Jamie: wettest*
Leah: TYPORETARDISM!!!!
Jamie: wettest
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