Which emotion is best described by the term "celos"?

The term "celos" is best translated to "jealousy" in English. Jealousy is an emotion characterized by feelings of insecurity, fear, and concern over a perceived lack of possession regarding a valued relationship, often stemming from the fear of losing that relationship to someone else. This term is often used in contexts involving personal relationships, where one may feel threatened by another individual’s closeness to someone they love.

In contrast, the other emotions—fear, joy, and sadness—do not capture the essence of "celos." Fear involves anxiety over a potential threat or danger, joy reflects happiness and positive emotions, and sadness pertains to feelings of sorrow or unhappiness. Jealousy distinctly encompasses a complex blend of emotions relating to rivalry and desire, making it the most accurate representation of "celos."