conditioned in buddhism refers to the fact that anything that exists, originates from something else.

so any one thing you examine will be “conditioned” on the previous things that cause it to appear

cause and effect basically

this has some philosophical implications, since all you are as a person is a bundle of emotions, mental patterns, etc that are ultimately conditioned

this leads to the buddhist view of no self, where there isn’t something that makes you “you”. just a bunch of responses to stimuli. some of those responses are thoughts of a self.