TSUMUGU · B2 (est.) · 字
偵
偵 ＝ 人 ＋ 貞
ㄓㄣ · zhēn
verb — to investigate, scout, detect
字源 FORM — what the parts do
貞聲zhēn — gives the sound
A person (人, 亻) sent to watch and find out — to investigate. 貞 zhēn carries the sound exactly. From the spy's quiet looking: 偵查, 偵探, 偵測 — to scout, to detect, to investigate.
故事 STORY — a scene to remember it by
一個人（亻）躲在暗處，盯著、記著——查的就是真相。
A person (亻) keeps to the shadows, watching, noting — it is the truth he is after.
字源記憶法
意 · Meanings
(本義)偵查、偵察— to investigate, scout常用
→偵探— a detective — one who detects常用
(本義) original meaning · → ⇒ each arrow = one more step of extension
關 · Related
貞zhēnthe bare phonetic — 貞 (with 卜 over 貝) means chaste, loyal; 偵 adds 亻 for the person doing the scouting