the mind > attention and judgement > importance > [noun] > that which is important > essential or central > upon which something depends > types of (2)
a matter of life and (also or) deatha1631
a matter of life and (also or) death: something on which the life or death of a person depends; (also in extended use) a matter of vital…
neck-word1650
a word on which one's ‘neck’ depends (cf. neck-questionn., neck-verse, n.).