Short for Welliot or Sir Wellington boot. It describes a person who is an idiot or someone who is highly competitive. Individuals tend to have a striking resemblance to Tim Henman and reside in Renmore. Example: Hes a bit of a Welly isn't he? or He's so competitive, that Welly.
WELLY
Meaning of WELLY in English
Slang English vocab. Английский сленговый словарь. 2012