Source: The Collaborative International Dictionary of English v.0.48
Stand-by \Stand"-by`\ (st[a^]nd"b[imac]`), n.
One who, or that which, stands by one in need; something upon
which one relies for constant use or in an emergency.
[1913 Webster]
standby
adj 1: ready for emergency use; "a standby generator"; "a
standby crew"
n 1: something that can be relied on when needed
2: an actor able to replace a regular performer when required
[syn: understudy, standby]