on life support

1. Literally, connected to machines that are keeping one alive, as by maintaining one's breathing or heart function. They said Aunt Edna won't ever be able breathe without a ventilator. How long do we keep her on life support? No, we can't put him on life support—he signed a do-not-resuscitate order.

2. By extension, struggling to remain viable or continue to exist. Our department's been on life support ever since our funding got slashed last year.