typonym
Analogous to synonym, typonyms are words that sound and mean the same but are spelled differently due to typographical error.
"Friend", "comrade" and "buddy" are synonyms while "friend", "firend" and "friedn" are typonyms.
typonym
A word that would be the same as another word if spelled without typographical error. This word is becoming increasingly relevant with the widespread usage of instant messaging services and rushed emails. When reading messages written in a hurry, one is alert for all words as well as their typographical counterparts.
The word 'answer', skimmed over quickly, could be mistaken for the word 'andrew'.