(Colloquially pronounced "glommin'") The act of making out in a particularly slobbery and intense manner; i.e. groping passionately while smacking lips together at a relatively high volume. It was derived from "glossy"- as in "lip gloss"- because both invoke a feeling of sticky, gooeyness that, as a third person observer, looks gross.
Person A: Oh ew! Gross!
Person B: What?
Person A: Veronica and Mark are glomming it up pretty hard over at the lunch tables! She's practically on top of him!
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