woolwort

adj.
Somebody who makes promises or says things but doesn't follow through with them. Gives excuses such as "too much homework" or "taking an extra course". Usually just lying to get out of it or to irritate people.

"sorry guys, i can't do that, i've got a lot of homework" *leaves*
"He's such a woolwort."

by Dr. H.B. Cromwell January 22, 2009