This is the 7892nd most frequent Japanese word.
圏外
"Outside the range" or "out of coverage."
It refers to the phone losing signal and thus being outside the service range of the network.
彼の携帯が圏外になった。
His cellphone went out of range.
It metaphorically indicates being outside an influential circle or industry segment.
彼はビジネスで成功したが、その業界では圏外だ。
He succeeded in business but is out of the circle in that industry.
It describes the area as being outside the scope or range for consideration as a tourist location.