post-haste
adverb
• with great speed or immediacy.
• "she would go post-haste to England"
Similar:
as quickly as possible,
as soon as possible,
ASAP,
without delay,
(very) quickly,
speedily,
swiftly,
without further/more ado,
with all speed,
promptly,
immediately,
at once,
straight away,
right away,
directly,
forthwith,
double quick,
p.d.q. (pretty damn quick),
pronto,
straight off,
straight,
instanter,
Origin:
mid 16th century: from the direction ‘haste, post, haste’, formerly given on letters.
