noun, noun which may take the genitive case particle 'no'
critically endangered; on the verge of extinction
Used in conservation contexts to describe species at extreme risk of extinction in the wild. Also used more broadly for anything about to disappear.
その鳥は絶滅寸前の種に指定されている。
That bird is designated as a critically endangered species.
この伝統工芸は絶滅寸前だ。
This traditional craft is on the verge of extinction.
絶滅危惧 is a broader term for 'endangered' or 'threatened', while 絶滅寸前 specifically means 'critically endangered' or 'on the brink of extinction'.
Compound of 絶滅 (extinction) and 寸前 (just before, on the verge of).