The term 'frolicky' refers to an energetic and playful mood, and its antonyms are those words that denote the opposite of that. Some of the antonyms for 'frolicky' include dull, boring, lethargic, apathetic, lifeless, inactive, unexciting, and serious. These words describe a state of being that is devoid of liveliness, enthusiasm, and fun. They are words that one would use to describe a situation that is mundane and uninspiring. Conversely, words that can be used as synonyms for 'frolicky' include playful, cheerful, lively, and exuberant. These words all imply a sense of joy and liveliness that is characteristic of a person or environment that is full of fun and playfulness.