To sneak up on someone and bean him with a heavy blow to the back of the head.
"Jim got thunked going home last night. Serves him right for walking in a dark alley with all his paycheck in his pocket.
By Gelya
Thunk
(verb) Used in fandom when a person (or alien creature) is looking gorgeous resulting in jaw dropping, drooling, falling out of chair, dying, or entering a comatose state.
(noun) The sound of someone dying or passing out as a result of sensory overload due to hotness.
Mg and Tan thunked when they saw a picture of Joe Flanigan's boxers.