[stand.by] n, pl stand.bys (1796) 1 a: one to be relied on esp. in emergencies b: a favorite or reliable choice or resource
2: one that is held in reserve ready for use: substitute -- on standby : ready or available for immediate action or use
[2]standby adj (1882) 1: held near at hand and ready for use "a ~ power plant" "~ equipment"
2: relating to the act or condition of standing by "~ duty" "a ~ period"
3: of, relating to, or traveling by an airline service in which the passenger must wait for an available unreserved seat "~ passengers" "a ~ ticket" [3]standby adv (1971): on a standby basis "fly ~"