• 労働ろうどう — labor, work
• 過労かろう — overwork
• 労力ろうりょく — effort, exertion
• 疲労ひろう — fatigue
• 労使ろうし — labor and management
• 労苦ろうく — hardship, toil

The kanji 労 is made of ⺶ (variant of 艹) and 力 (power), combining the ideas of action and fatigue. Originally associated with labor and exertion, it can also convey appreciation or sympathy for effort, as in “ご苦労様”.

彼かれは 毎日まいにち労働ろうどうしています。
He works hard every day.

過労かろうで 倒たおれた。
He collapsed from overwork.

“ロウ” is the most common reading. The kun-yomi “いたわる” (to sympathize or show concern) is rare and typically used in classical or poetic contexts.