Forthwith and Posthaste

Forthwith

Forthwith adverb - Without delay.
Usage example: if the fire alarm rings, leave the building forthwith
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Synonyms for Forthwith

Posthaste and forthwith are semantically related. In some cases you can use "Posthaste" instead an adverb "Forthwith".

Posthaste

Posthaste adverb - With great speed.

Forthwith and posthaste are semantically related. Sometimes you can use "Forthwith" instead an adverb "Posthaste".

Both words in one sentence

Cite this Source
Posthaste and Forthwith. (2016). Retrieved 2026, August 15, from https://thesaurus.plus/related/forthwith/posthaste
Forthwith & Posthaste. N.p., 2016. Web. 15 Aug. 2026. <https://thesaurus.plus/related/forthwith/posthaste>.
Posthaste or Forthwith. 2016. Accessed August 15, 2026. https://thesaurus.plus/related/forthwith/posthaste.
Google Ngram Viewer shows how "forthwith" and "posthaste" have occurred on timeline