posthaste
2 synonyms for posthaste, grouped by meaning and by how common each one is.
Adv — Very quickly, without any delay.
Synonyms
Everyday swaps
Common words most readers know — safe in any writing.
Less common
Still standard English, but they carry more weight.
Etymology
From the former instruction on letters ‘haste, post, haste’, later reinterpreted as a compound of post + haste.
Full origin of posthaste →