A term coined to describe obsessed Southampton football fans (also known as scummers) by their historically vastly more successful neighbours, Portsmouth.
It is basically a mixture of Envious and Devoid, describing a scummer who is so envious of Pompey's history, fans, League and Cup successes - whilst devoid of any individual personality or meaningful success of his own team - that he is instead obsessed with anything and everything that happens at Pompey.
Basically an obsessive online keyboard-warrior.
Hark at that bunch of keyboard warrior envoids who are swamping the Pompey message boards - they are obsessed, mate!
'Ere Bob, did you see that dinnyscummer envoid on the News site the other day? The little pony fiddler was so obsessed with Pompey news that he has created 20 different log-on addresses just to make the same, inane points and to look like he has friends!