na-adjective
Describes a fast walking pace or quick movement. Most often used adverbially as 足早に.
See also: 足早に
彼は足早に駅へ向かった。
He headed briskly toward the station.
足早な足音が近づいてきた。
Quick footsteps approached.
na-adjective
Describes the swift passage of time. Less common than the walking sense.
足早に過ぎる時間を惜しむ。
I regret the swift passage of time.