Modified by adjectives having adverbial force: someone who lives (in a specified way, for a long time, etc.), as easy liver, long liver, etc. See…

a person who is technically alive, but otherwise unresponsive and incapable of participating in life; cf. living dead, n.

With plural agreement (usually with the). Living-dead people considered as a class; esp. the class of people who lead a miserable or empty existence.

A person who is involved in something, esp. a career or job, for life (or a very long period of time), either through commitment and passion or…