skylark

a kind of bird – song bird – related to the larks – small with brown feathers above streaked (speckled) with black, and pale brown or grey underside, a blunt moveable crest (= a tuft of feathers) on the head, sturdy medium-sized legs with relatively long toes, flat tail; size: 7-8 inches long, and weight: —; feeds on seeds and insects; lives for 2-8 years; found in Europe, Asia, and the mountains of North Africa

Special Features:
The skylark is noted for its melodious call (song), especially when it sings while flying (soaring) vertically upwards.

Figures of Speech:

a skylark in flight

to skylark (verb) =

(a) to play about with high spirits, light-heartedly

(b) to act as a fool

skylarker = a burglar (thief), pretending as a worker, goes about a place in order to find out the lie of the land (what things are there, where they are placed, etc. so that he/she can steal them later easily)