noncasual

/nɑnˈkæʒuəl/
adjective
  1. Not casual; formal, serious, or deliberate in nature.
    • Their relationship was noncasual; they were planning a future together.
    • The meeting had a noncasual tone, with everyone taking careful notes.
    • The dress code for the event is noncasual, so please wear a suit.
Antonyms
What does "noncasual" mean? | whatsthatwordmean | whatsthatwordmean