The word "overjealous" means excessively or unreasonably jealous, possessive, or suspicious. The antonyms for the word "overjealous" include confidence, trust, relaxed, easygoing, nonchalant, indifferent, unconcerned, disinterested, and trusting. Someone who is confident in their relationship and trust their partner with no unnecessary suspicion or possessiveness can be considered the opposite of overjealous. Being relaxed and easygoing in your approach to your relationship can also be seen as antonyms to being overjealous. Additionally, someone who is indifferent, unconcerned, or disinterested in their partner's actions can be seen as the opposite of overjealous.