The antonyms for the word "more larking" can be responsible, serious, and solemn. If someone is more responsible, they are less likely to play around and joke around. Serious and solemn mean that a person is less likely to participate in playful activities and prefers more serious or formal environments. Other antonyms for "more larking" include mature, measured, balanced, and sensible. In contrast, a person who is more larking is playful, mischievous, and carefree. It's important to remember that there's a time and place for both serious behaviors and larking around, and each has its own benefits and drawbacks.