noun
good walker; tireless walker
Describes a person who walks a lot without tiring, or who is fond of walking. Often used in a positive, admiring way.
祖母は足まめで、毎日何キロも歩く。
My grandmother is a tireless walker and walks several kilometers every day.
彼は足まめだから、旅行のときもずっと歩き回っている。
He's a good walker, so even when traveling he's always walking around.
健脚 refers more to having strong, sturdy legs for walking, while 足まめ emphasizes the habit or quality of walking a lot without tiring.
Compound of 足 (foot/leg) and まめ (diligent, hard-working). The exact origin of まめ is uncertain, but it conveys the idea of being tireless and diligent in walking.