na-adjective
diligent; hardworking; conscientious
Describes a person who works steadily and reliably, often with a sense of earnestness and attention to detail. Common in everyday speech.
彼はまめに日記をつけている。
He diligently keeps a diary.
まめな人は信頼される。
A hardworking person is trusted.
na-adjective
Dated usage for being in good physical condition. In modern Japanese, 元気 or 健康 is more common.
おかげさまで、まめにしております。
Thankfully, I am in good health. (archaic phrasing)
na-adjective
Dated usage for being loyal or sincere. Today, 忠実 (ちゅうじつ) or 誠実 is normally used for this meaning.
彼は主君にまめに仕えた。
He served his lord faithfully. (archaic phrasing)