To be ignored, cut off, brushed off, blown off, shoved aside, and otherwise snubbed.
'Mabbed' is a reference to the character of "
Queen Mab" in the made for TV series, "Merlin". Upon being ignored and forgotten,
Queen Mab lost all of her power, and ceased to exist.
In short, she was a troll. What happens to a troll when you ignore them and don't give them the reaction they want, or the
time of day? They get bored, and go elsewhere. Ignore a troll, and they lose their power. Forget them, and they become as useful as a corpse.