as happy as a lark Definition

lark¹
noun

1. Any of various different kinds of bird, but especially the skylark, that are usually gregarious, brownish in colour, ground-nesting and characterized by their tuneful song which they often deliver while in flight.

Idiom: as happy as a lark

Extremely carefree.

Idiom: get up with the lark (be up with the lark)

To be up and about very early in the morning.

Etymology: Anglo-Saxon lawerce.