Gnomish
cuithos
noun. life (period of life); living, livelihood
cuithos hû le mui
a cat and dog life
Beware, older languages below! The languages below were invented during Tolkien's earlier period and should be used with caution. Remember to never, ever mix words from different languages!
A word appearing as G. cuithos “life (period of life); living, livelihood” in the Gnomish Lexicon of the 1910s, a noun form of G. cuitha- “am alive” (GL/27).
Neo-Sindarin: For purposes of Neo-Sindarin, I’d update this word to ᴺS. cuithas using the later abstraction noun suffix -as, and would assume it is an abstraction based on ᴺS. cuith “[biological process of] life”. I would use it to refer both to the means of providing for one’s life (= “livelihood”) as well as a period of time within one’s life, as opposed to one’s entire lifetime which would be ᴺS. cuilvorn.