Which method$($s$)$ of definition does Lars Eighner use in the following passage?

I began Dumpster diving about a year before I became homeless. I prefer the term

scavenging. I have heard people, evidently meaning to be polite, use the word foraging, but

I prefer to reserve that word for gathering nuts and berries and such, which I also do$,$

according to the season and opportunity."

by category

by synonym and by negation

by negation and by synonym

by classification