One way to hold this word: a line that used to run between you and someone, and is now dead. The people have not disappeared. The is still your , the number is still in your phone — nobody calls. What makes estranged heavy is exactly that the closeness is still on record while the contact has stopped, so a familiar person has turned into a stranger. English then runs the same dead line between a person and a thing: a hometown, a company, a team you gave your childhood to.
The source describes this word as meaning 'having become a stranger, of one who formerly was close', and lists it as the past participle of the verb estrange. So the stranger inside the word is not decoration: the form says someone was made strange.
資料裡把這個字解釋為「本來親近的人，變成了陌生人」，並且標明它是動詞 estrange 的過去分詞。所以字裡的 strange（陌生）不是巧合：這個形態說的就是「被變成了陌生人」。
Packet evidence: Wiktionary entry 'estranged' — adj gloss 'Having become a stranger, of one who formerly was close…' (wikt:estranged:adj:0) and verb gloss 'simple past and past participle of estrange' (wikt:estranged:verb:0).
Two branches
人跟人之間斷了線
這一支就是核心畫面本身：關係還在名義上，往來已經停了。
adjective · B2
No longer seeing or speaking to a relative or a close friend, usually after an argument or after years of bad feeling. The two people are still related, or were once close, but the relationship has stopped.
疏遠的；斷絕往來的
人跟事物之間斷了線
線的兩端換了一端：另一頭不再是人，而是一個地方、一個團體或一種信念。斷掉的方式完全一樣——東西還在，歸屬感沒了。
adjective · C1
No longer feeling any connection with a group, a place, a belief or an activity that used to be important in your life.
感到疏離的；失去連結的