lark

Very happy; contented. I've been happy as a lark ever since we moved to the countryside. Johnny's in a bit of a bad mood, but just give him a new toy to play with and he'll be happy as a lark.

On a whim or fancy; for fun or as a joke. On a lark, we all decided to ditch our Friday classes and drive to New York City for the weekend.

Awake, out of bed, and active at a particularly early hour of the morning. I don't know how he does it, but my husband has gotten up with the lark every morning of his life. I won't have another pint, thanks. I have to be up with the larks tomorrow, so I'd better head home soon.

Awake at a particularly early hour, especially at or before sunrise (i.e., the hour when larks sing). Primarily heard in UK. I'm sorry, but I have to get going. I have to be up with the lark tomorrow. Mum is up with the lark every day to prepare breakfast for the farmhands.

for a joke; as something done for fun. For a lark, I wore a clown's wig to school. On a lark, I skipped school and drove to the beach.

to be awake and out of your bed early in the morning You were up with the lark this morning!

Also, happy as a lark; happy as a clam (at high tide). Extremely glad, delighted, very cheerful, as in He was happy as the day is long, or When she heard the news she was happy as a lark, or Once I got the test results I was happy as a clam at high tide. The first of these similes dates from the late 1700s. The second alludes to the lark's beautiful, seemingly very happy, song. The third, from the early 1800s, alludes to the fact that clams can only be dug at low tide and therefore are safe at high tide; it is often shortened to happy as a clam.

Also, lark about. Have a noisy, exuberant good time. For example, We were larking it up when the supervisor walked in, or He's always larking about at night. These expressions employ lark in the sense of "to frolic," a usage dating from the early 1800s. Also see cut up.