When you develop a small to large callus on the tips of your thumbs from excessive texting. Or when you develop "pads" or flattened harder areas on the tips of your thumbs.
"Dude, I think i've got texter's thumb, just look at this callus."

or

"Wow, that is some impressive texter's thumb."
"I know, I think i text too much."
by JaxinsWords January 8, 2010
Get the Texter's thumb mug.
When an individual suffers repetitive strain injury (RSI) in the first digit of the hand (thumb) from excessive text messaging.
Bill: 'Dude I wasn't ignoring you'

Bob: 'How do you explain that then'

Bill: 'My texter's thumb preventing me from contacting you!'
by yami100 June 13, 2010
Get the Texter's Thumb mug.