noun, noun which may take the genitive case particle 'no'
final stage; terminal stage
Used in medical contexts for terminal illness, as well as more broadly for the last phase of a process or life.
He is a doctor who stays close to terminal patients.
This project has entered its final stage.
Compound of 終末 (shūmatsu, 'end, close') + 期 (ki, 'period, stage'). The reading is standard on'yomi.