A person with poor thumb dexterity. Can be used as either a noun or an adjective. Portmanteau of thumb and unco, the latter a popular Australian abbreviation of 'uncoordinated', meaning clumsy or possessing poor manual dexterity. Many people from Generation X and before are thuncos, not having grown up with text messaging, video games and other agents of repetitive strain injury.
I'll be a while typing this text message, I'm a total thunco.

Look at him trying to play Halo! He's so thunco!
by neonwombat January 17, 2009
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