投

By extension, it can also mean “to hurl,” “to send,” or “to commit (oneself to something).”

Phono-semantic compound:

手 (수, “hand”) – provides the meaning (an action done with the hand)

殳 (수, “club, striking weapon”) – provides the sound (tu / tóu) and implies forceful motion

Originally, the character depicted the act of throwing something by hand, often a stick or weapon.

This included:

- throwing weapons

- hurling objects

- casting something forward with intent

Over time, its meaning broadened from literally throwing objects to also sending forth ideas, efforts, or even entrusting oneself (as in 投身 “to throw oneself into something”).

투구 (投球) — pitching a ball

투표 (投票) — voting

투신 (投身) — devotion, self-sacrifice

투자 (投資) — investment

Because throwing implies commitment, 投 naturally developed meanings like: commit, submit, devote, invest.

This metaphor is widespread across East Asian languages.

Related characters:

抛 — to toss (casual or light tossing)

擲 — to hurl (forceful hurling)

投 — to throw / commit (deliberate, directed throwing)

資 — resources

丟 — discarding, careless throw

投資 — investment

投 differs from other “throw” characters it emphasizes intent and direction, not randomness.