adjective/de.ɡœ.las/
bloody disgusting; rank; yucky; gross; cool, wicked, amazing
“2016 July 3, Olivier Philippe-Viela, "Mort de Michel Rocard: «La politique est dégueulasse»... Les cinq phrases à retenir de Michel Rocard", 20 Minutes, quoting a phrase from 1991 April 25 by Michel Rocard.”
Synonyms: infect, immonde
From dégueuler (“to vomit”) + -asse. Compare English vomitrocious.