Fetching details from the dictionary...

another place; somewhere else; strange parts
outside (one's family or group); someone else; other people
not caring for; being indifferent to; taking little notice of; ignoring; neglecting
この店が気に入らないなら余所へ行こう。
If you don't like this store, let's go somewhere else.
ここは、余所とはルールが違う。
The rules here are different from those elsewhere.
「余所の人にはついていっちゃダメよ」と子供に言い聞かせた。
"Don't go off with people from outside our circle," I told my child firmly.