Definify.com
Webster 1913 Edition
Aback
1.
Toward the back or rear; backward.
“Therewith aback she started.” Chaucer.
2.
Behind; in the rear.
Knolles.
3.
(Naut.)
Backward against the mast; – said of the sails when pressed by the wind.
Totten.
To be taken aback
. (a)
To be driven backward against the mast; – said of the sails, also of the ship when the sails are thus driven.
(b)
To be suddenly checked, baffled, or discomfited.
Dickens.
Ab′ack
(ăb′ak)
, Noun.
An abacus.
[Obs.]
B. Jonson.
Webster 1828 Edition
Aback
ABACK
,adv.
Towards the back; on the back part; backward. In seamen's language it signifies the situation of the sails, when pressed back against the mast by the wind.
Taken aback, is when the sails are carried back suddenly by the wind.
Laid aback, is when the sails are purposely placed in that situation to give the ship sternway.