孔

by extension, surname “Kong” (as in Confucius 孔子)

Compound character:

子 (자, child) – semantic component.

乙 (을, the 2nd heavenly stem, also hook-like stroke) – represents a bent/hooked shape.

Together: “a child emerging through an opening” - hole, aperture.

孔子 (공자) — Confucius

氣孔 (기공) — pore, air hole

漏洞孔 (누공) — leak hole, perforation

孔洞 (공동) — cavity, hollow

As a surname: 孔 (Khổng/Kong) — most famously in 孔子 (Confucius).