1. superlative form of lark; most playful, mischievous, or lighthearted in manner or spirit
Usage: informal; chiefly British

Examples

• She was in the larkiest mood, joking and laughing all evening.
• His larkiest antics during the party had everyone in stitches.
• The larkiest members of the group were always up for a prank.
• That was the larkiest thing he'd done all week.
• She gave him a larkiest grin before running off to hide.