Working Earnestly
Sincerity, Diligence, Effort
noun, verbal noun
A miner works with such sincerity that her arms and legs start turning rust-colored from working earnestly. All the clay and rocks she's putting her effort into digging are turning her the same color. That color is how you know someone works with serious diligence.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
お婆ちゃんが丹誠込めて育てたトマトだよ。
These are the tomatoes that Grandma worked earnestly to raise.
この時計は、一つひとつ丹誠に仕上げられています。
Each of these watches is crafted with painstaking care.
医師たちは患者のために丹誠を尽くした。
The doctors wholeheartedly devoted themselves to their patients.
彼女は丹誠を込めて料理を作り、親戚一同を出迎えた。
She prepared the meal with sincere care and welcomed all her relatives.