An adjective used to metaphorically refer to a person as if they were living in squalor conditions, possessesing poor language skills, dirty or tacky clothing and generally having no regard for, nor prior exposure to, social etiquette. A derogatory reference to someone who could be likened to someone who posseses a small amount of crack, a crack pipe, an unusual amout of cardboard and a rusted shopping cart for a car. A serious insult....
"EEEEEEEEwwww....that girl is totally undabridge"....wow, check out that car, the driver is definitely undabridge....
Aborigines who live under a bridge. They mostly sleep all day but at night the venture out to bum durrys and money off other people. Mostly found in Townsville.
Man 1: I went walking through the mall the other day and one of those damn underbridgines came out and asked for a smoke!
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Girl: I swear everytime I walk over that bridge those underbridgines upskirt me.