far gone

Short definition from Wiktionary

Adjective

1. 1
   Used other than figuratively or idiomatically: see far, go, gone.
2. 2
   Almost entirely used up or elapsed.
3. 3
   At an advanced stage of decline, disability or alteration, from some process, such as disease, decay, intoxication, infatuation, or moral weakness.
4. 4
   Alternative form of far gone.