A paedophile who conducts his vile activities by mail (be it snail- or e-) - the paedo equivalent of the Unabomber.
"Police today are concerned after an unabummer molested a child by post."
by Spetswalshe August 15, 2008
1 more definition
some one who likes a nice pink arse and balls with no hair on them (a paedophile).
hey lets batter the shit out of that una bummer for the school assembley
by clarkycat September 09, 2009