lark¹ / lärk/ • n. a small ground-dwelling songbird (family Alaudidae), typically with brown streaky plumage, a crest, and elongated hind claws, and with a song that is delivered in flight.lark² inf. • n. something done for fun, esp. something mischievous or daring; an amusing adventure or escapade: I only went along for a lark.• v. [intr.] enjoy oneself by behaving in a playful and mischievous way: he jumped the fence to go larking the rest of the day.DERIVATIVES: lark·ish adj. lark·y adj.

lark Any of several small birds, known for their melodious songs. Most common in Europe are the woodlark (Lullula arborea), skylark (Alauda arvensis) and shorelark (Eremophila alpestris). All are mottled brown. Depending on where they live, they feed on insects, larvae, crustaceans or berries. Length: to 18cm (7in). Family Alaudidae.

lark the lark's song is delivered on the wing, and traditional allusions refer to its early singing, the strength and sweetness of its song, and the height to which it soars above its nest.
be up with the lark be up very early in the morning.

See also if the sky falls we shall catch larks.

lark1 bird known for its morning song. OE. lāwerce, lāwerce, corr. to MLG., MDu. lēwer(i)ke (Du. leeuwerik), OHG. lērahha (G. lerche), ON. lævirki (perh. from Eng.); of unkn. orig. The Sc. var. laverock descends from ME. laverok. comp. larkspur XVI (larkes spur); so called from the spur-shaped calyx.

lark2 (colloq.) play tricks, frolic. XIX. poss. repr. dial. lake play, sport—ON. leika = OE. lācan.
Hence sb. XIX.