This idiom means to do something just for fun. Here are some example sentences.
Yes, I did buy this sports coat on a lark. The lark sings from the meadow.
Don't just lark around, help us.The lark has a beautiful song.
*Something extremely easy to accomplish, succeed in, or to obtain: That exam was a lark.
There are two common meanings for the word 'lark'. 1) To do something for quick fun or a prank. "We skipped school and headed to the beach on a lark". 2) A lark is also a type of songbird. "Each morning I listen as the lark sings beautifully from the meadow." (*I wrote this original answer, but hadn't signed in so it went to anonymous 'contributor'.)
Happy as a lark is the cliché or overused expression.
Shannon Lark goes by Lark.
Yes. Lark is a noun.
A young lark is called a chick
Lark Oxler's birth name is Lark Suzanne Oxler.
Lark Taylor's birth name is John Lark Taylor.
Is lark voorhies black
A female lark is called a hen