Wordnet 3.0
ADVERB (1)
1.
as fast as possible;
with all possible haste;
- Example: "send it to me post-haste"
The Collaborative International Dictionary of English v.0.48:
Posthaste \Post`haste\, adv.
With speed or expedition; as, he traveled posthaste; to send
posthaste. --Shak.
[1913 Webster]
The Collaborative International Dictionary of English v.0.48:
Posthaste \Post`haste"\, n.
Haste or speed in traveling, like that of a post or courier.
--Shak.
[1913 Webster]
WordNet (r) 3.0 (2006):
post-haste
adv 1: as fast as possible; with all possible haste; "send it to
me post-haste"