(zoology, of birds) Hatched from the egg already covered in down and with eyes open; capable of leaving the nest within a few days.

(biology) The condition of being precocial

(biology) In a precocial manner

Characterized by exceptionally early development or maturity. / Exhibiting advanced skills and aptitudes at an abnormally early age.

In a precocious manner.

The condition of being precocious

(medicine) Partial pubertal development resulting from gonadotropin-independent oestrogen production in prepubertal girls.