From Longman Dictionary of Contemporary Englishlark about/around phrasal verb British English informalENJOY/LIKE DOING somethingto have fun by behaving in a silly way SYN mess about A couple of boys were larking about in the pool. → lark→ See Verb table
Examples from the Corpus
lark about/around• But then you realise that there's no room whatsoever for larking about and enjoying yourself.• Mr Grainger claims his 13-year-old son James was punched in the chest when he was caught larking about in lessons.• The kids are larking about in the steam-filled room, and the girl seems grateful for adult conversation.• Stu would be laughing and larking about with his mates at the wallpaper shop.• They all go bicycling together and run across bridges and lark about, yes? 