What is the difference between condescending and patronizing?

Very few words in English have exactly the same meaning; even words which appear to be entirely synonymous often will be found to have small differences in certain contexts. The words condescending and patronizing present a fine example of this. At first glance these words appear to be defined somewhat circularly: condescending often has the word "patronizing" in its definition, and patronize is defined, in part, as “to adopt an air of condescension toward.”

But both of these words have specialized senses that lend a shade of meaning to their synonymous senses. Patronizing can mean "giving support to" or "being a customer of," suggesting that the "condescending" sense implies superiority gained through a donor-dependent relationship.

The verb condescend used to be free of any hint of the offensive superiority it usually suggests today. It could mean literally "to go or come down" or, figuratively, "to willingly lower oneself to another’s level," senses that are still occasionally encountered in writings on the Bible. The idea of self-consciously lowering oneself is implied in the "patronizing" sense of condescending.