The verb lacerate means to cut or tear. So the envelope that gave you that nasty paper cut? It lacerated your finger.
Something usually needs to be sharp or jagged to lacerate you, like broken glass or a sharp stick. You won't be getting lacerated anytime soon by lace or cotton balls, that's for sure. But watch out for sharp-tongued people hurling hateful words your way; those snide remarks and personal digs can lacerate feelings like a knife slicing through butter.