I think Wikipedia answers this question quite well:
An audiophile is a person who is enthusiastic about high-fidelity sound reproduction. An audiophile seeks to reproduce the sound of a live musical performance, typically in a room with good acoustics. It is widely agreed that reaching this goal is very difficult and that even the best-regarded recording and playback systems rarely, if ever, achieve it.
Audiophile values may be applied at all stages of music reproduction: the initial audio recording, the production process, and the playback, which is usually in a home setting. In general, the values of an audiophile are seen to be antithetical to the growing popularity of more convenient but lower quality music, especially lossy digital file types like MP3, lower definition streaming services, and inexpensive headphones.
I don't consider myself an audiophile because I'm not primarily looking for the original sound. Rather, I look for the best sound (for me) with the best possible quality.
In my opinion, an audiophile should not use tone controls on their amplifier and should only use master (FLAC) files.
Thomas