喉 is more formal/medical; in everyday speech, 嗓子 (sǎngzi) or 喉咙 (hóulóng) is more common for 'throat.' 喉 appears in compounds like 咽喉 (yānhóu, pharynx) and 喉舌 (hóushé, mouthpiece).
memory
口 (mouth) + 侯 (marquis, phonetic) — the passage below your mouth. The marquis part gives the 'hóu' sound.
