One who has the ability to think for themselves and uses it.
If you had to read the example, you are not a thunker!
by Robert L Wooten September 27, 2006
1 more definition
To make a large mistake like to shoot a 8 on a par 4 golf hole, or to totally screw something up, like ruin a term paper for school
Man, thats the worst thunker i have ever shot in one round of golf
by Johannathon June 17, 2005