掌握
zhǎngwò · HSK 5
know well
✋ 掌 = palm + 握 = grip; palm-grip means to master or have in hand
掌 (palm of the hand) plus 握 (to grasp/grip) literally combines to palm-grip. The compound extends from physically holding something to figuratively mastering a skill or having a situation firmly in hand.
握 — hand 扌 + 屋 wū (phonetic)
握 is a semantic-phonetic compound. The hand radical 扌 carries the meaning — actions done with the hand — while 屋 supplies the sound. The original sense is to grasp or hold tightly in the fist, which still matches its modern meaning.