• 了解りょうかい — understanding; “got it” / roger
• 終了しゅうりょう — end; termination; program ending
• 完了かんりょう — completion; finished state
• 了承りょうしょう — consent; acknowledgement
• 修了しゅうりょう — completion of a course or program
• 投了とうりょう — resigning in shogi or go
• 了見りょうけん — one’s outlook; way of thinking (often critical)

The kanji 了 is a very small character, originally linked to the idea of something being fully formed or brought to an end. In modern Japanese it appears mostly in compounds that describe a task being finished or a situation being understood — like 完了かんりょう, 終了しゅうりょう, and 了解りょうかい.