stel ‧ lar /ˈstelə $ -ər/ BrE AmE adjective [only before noun]
[ Date: 1600-1700 ; Language: Late Latin ; Origin: stellaris , from Latin stella 'star' ]
1 . relating to the stars ⇨ ↑ interstellar
2 . especially American English extremely good:
the company’s stellar growth
McKellen gave a stellar performance.
3 . go stellar British English informal if a ↑ pop band, actor etc goes stellar, they become very popular and famous:
There’s a stand-up comedian, and my sources tell me he is about to go stellar.