Definition of yas in English:

yas

(also yass, yaass)

Pronunciation /yas/ /jæs/ /yäs/ /jɑs/

exclamation

informal
  • Expressing great pleasure or excitement.

    • ‘Yas! Now this is truly punk rock!’
    • ‘free wine and cheese and candy, yass’

Origin

Mid 19th century (originally in representations of a regional pronunciation of ‘yes’): representing an informal or exaggerated pronunciation of yes.