秘密
ひみつ · himitsu · JLPT N3 · noun
secret
🤫🔒 himitsu sounds like he meets you: a secret meeting nobody may know about
秘 means hidden, as in 秘書 (secretary). 密 means close or tightly kept, as in 密室 (sealed room). Hidden plus tightly kept gives secret. The sound hook: he meets you, and it stays himitsu.
密 — 宀 roof + 必 (phonetic) + 山 mountain
Originally referring to a hidden, sheltered place in the mountains, 密 combines 宀 (roof/cover) over 必 (phonetic) with 山 (mountain) at the base. The meaning extended from 'secluded mountain hideaway' to 'dense, close, secret'. Today it commonly means dense, intimate, or secret.