Which term refers to a participant in Latin?

The term "particeps" is the correct choice for referring to a participant in Latin. Its etymology is rooted in the combination of two Latin words: "pars," meaning part, and "capere," meaning to take or seize. Thus, "particeps" conveys the sense of someone who takes part in something, embodying the idea of participation or being involved.

In contrast, other options pertain to different meanings. "Arbitror" translates to judge or consider, emphasizing a role of assessment rather than participation. "Furor" means frenzy or rage, which describes a state of intense emotional disturbance and does not relate to participation. Similarly, "vigilia" refers to wakefulness or vigilance, often associated with staying alert or watching, rather than participating in an activity. Understanding these distinctions reinforces why "particeps" is the appropriate term for a participant in Latin.