If you epitomize something, you’re a perfect example of that thing. If you never get nervous when playing basketball and can always make that last-second shot, your teammates might say you epitomize mental toughness.
A person can epitomize something — usually an abstract quality, like grace or greed — but epitomize can apply to other things as well. A popular band might epitomize the spirit of the new decade, which means it has all the main characteristics associated with the era's music, like long folksy beards, pretty harmonies, and earnest lyrics. A frustrating situation at work involving careless coworkers might make you say that they epitomize everything that’s wrong with your job.