DeleteElements

DeleteElements[list, {e1, e2, ...}] removes all instances of elements ei from list.

Examples

Remove elements:

DeleteElements[{a, b, c, b, a}, {a, b}]
(* {c} *)

Remove limited instances:

DeleteElements[{a, a, a, b, b}, 1 -> {a}]
(* {a, a, b, b} *)

Please visit the official Wolfram Language Reference for more details.