Same two characters as 德性, moral character, but here the second syllable is toneless and the meaning is the opposite of praise. If the sentence is mocking how someone looks or behaves, the reading is déxing.
register
Rude and mocking, said about someone you are looking down on. It normally follows 那 or 这 with the measure word 副, so the shape you hear most is that pattern plus the noun. Never aim it at someone you are being polite to.
