posthaste

/ˌpoʊstˈheɪst/
adverb
  1. With great speed or urgency; as quickly as possible.
    • The team repaired the leak posthaste to prevent flooding.
    • The doctor was called to the emergency room posthaste.
    • She finished her homework posthaste so she could go outside.
Antonyms
What does "posthaste" mean? | whatsthatwordmean | whatsthatwordmean