IPA: /ˈblʌdˌsteɪnd/
KK: /ˈblʌdˌsteɪnd/
Having marks or spots of blood on it, often indicating violence or injury.
The detective examined the bloodstained shirt for clues.
Bloodstained → It is formed from "blood" (from Old English "blōd", meaning the red liquid that circulates in the bodies of humans and animals) and "stained" (from Old English "stǣnan", meaning to mark or color). The word "bloodstained" describes something that has been marked or colored with blood.
Think of the red liquid that circulates in our bodies ('blood') being 'marked' or 'colored' ('stained') — that's why bloodstained means something that has blood on it.
No commonly confused words.