The kanji 研 primarily conveys the meaning of "to grind," "to polish," "to study," or "to research." It suggests a process of refinement, improvement, or in-depth investigation. It implies bringing something to a better state through focused effort.

・On-yomi (音読み): ⚫︎ ケン (ken) ・Kun-yomi (訓読み): ⚫︎ と（ぐ） (to(gu)) - to sharpen, to grind ⚫︎ みが（く） (miga(ku)) - to polish, to brush up

⚫︎ 研究 (kenkyuu) Translation: Research; study ⚫︎ 研磨 (kenma) Translation: Polishing; grinding; refinement ⚫︎ 研修 (kenshuu) Translation: Training; study

The kanji 研 is a phono-semantic compound (形声文字). It combines the radical 石 (研 is composed of 石, which means "stone" or "rock") and the phonetic component 幵 (pronounced ケン in Chinese). The original meaning of 研 was related to sharpening or polishing stones. The 石 (stone) radical indicates the material being worked on, and the phonetic component 幵 provides the sound. Over time, the meaning expanded to encompass the broader concepts of studying and research, which involve refining and improving knowledge, similar to polishing a stone to make it smooth.