He knew he had to act quickly to meet the deadline.
hurry up
Frequency:
60
%
We need to hurry up and finish this project posthaste.
promptly
Frequency:
50
%
She always responds promptly to any requests.
swiftly
Frequency:
45
%
The package was delivered swiftly, just as requested.
Idiomatic Expressions for posthaste
Phrase: send something posthaste
Meaning: to send something with great urgency or speed
Usage: The package was sent posthaste to ensure it arrived on time.