A textonym is a word which becomes ambiguous when using predictive text due to having the same button combination as other unrelated words. They often make a text confusing or incomprehensible.
Particularly prominent in drunk texting.

He = If
Me = Of
Book = Cool
Soon = Room

When using predictive text to write an SMS, sometimes an unexpected word of similar / humorous meaning may pop up.

Pint / shot / riot

Kiss / lips

Shag / rich

Sips / piss

Cock / anal

Dual / fuck

In text or SMS messaging, a textonym is a word that is typed using the same sequence of keys on a phone's numeric keypad as another word.

Words that are related in their combination of button strokes, usually on a phone's number-pad and with T-9 or similar methods.

Variant/Incorrect spelling of txtonym.

Two or more words that are spelled using the same series of keys in a text message.

"Me" and "of" are both entered using 6-3.

Also "good", "home", "gone", "hood", "hoof", and "goof" are textonyms.

The abbreviated vertions of words into text such as brb, or ttyl