noun
person on standby; person on a waiting list; person waiting
General term for someone who is waiting for their turn, such as on a waiting list, in a queue, or on standby for a service or event.
人気のレストランは常に待機者が多い。
Popular restaurants always have many people on the waiting list.
キャンセルが出たので、待機者に連絡した。
Since there was a cancellation, I contacted the person on standby.
noun
person in quarantine; person isolating
Used specifically for someone who is quarantining or isolating, often in medical or public health contexts. This usage became more common during the COVID-19 pandemic.
濃厚接触者は待機者として自宅待機を求められた。
Close contacts were asked to stay home as persons in quarantine.
待ち人 is a more poetic or literary term for someone you are waiting for, often with emotional nuance, whereas 待機者 is neutral and functional.
Compound of 待機 (standby, waiting) and 者 (person). The quarantine sense is a modern extension of the waiting concept.