IPA: /ˈʃædəʊə/
KK: /ˈʃædoʊər/
A person who follows or observes someone closely, often without their knowledge.
The detective acted as a shadower, keeping an eye on the suspect from a distance.
Shadower → It is formed from "shadow" (from Old English *sceadu*, meaning shade or shadow) and "-er" (meaning a person who). A shadower is a person who casts a shadow or follows closely behind someone, often in a secretive manner.
Think of someone who is a 'person' ('-er') that creates a 'shade' ('shadow') — this helps you remember that a shadower is someone who follows closely, like a shadow.