Dictionary.com
Thesaurus.com
Synonyms

aback

American  
[uh-bak] / əˈbæk /

adverb

  1. toward the back.

  2. Nautical. so that the wind presses against the forward side of the sail or sails.


adjective

Nautical.
  1. (of a sail) positioned so that the wind presses against the forward side.

  2. (of a yard) positioned so that its sail is laid aback.

idioms

  1. taken aback, surprised and disconcerted.

    I was taken aback by his harsh criticism.

aback British  
/ əˈbæk /

adverb

    1. startled or disconcerted

    2. nautical (of a vessel or sail) having the wind against the forward side so as to prevent forward motion

  1. rare towards the back; backwards

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

aback More Idioms  
  1. see take aback.


Etymology

Origin of aback

First recorded before 1000; Middle English abak, Old English on bæc “to the rear”; a- 1, on, back 1

Explanation

To be taken aback is to be taken by surprise. You might be taken aback when your grandmother suddenly demonstrates her yodeling skills. When you see the adverb aback, it almost always follows the verb "to take." When you're taken aback, you're startled, often by another person's actions. If someone makes a rude comment at a dinner party, for example, you'll be taken aback. The word dates from about 1200, and it comes from the Old English on bæc, "at or on the back." It was first used as a nautical term for a strong wind flattening the sail against the ship's mast.

Keep Reading on Vocabulary.com

Vocabulary lists containing aback

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Smart said she was a little taken aback when she first learned how things would pan out for aging comic Deborah Vance and her mentee Ava Daniels, played by Hannah Einbinder.

From Barron's • Apr. 6, 2026

The man was clearly taken aback, some of the other patrons chuckling in surprise, the Dodger pulse of this town clearly resonating in a completely unusual fashion.

From Los Angeles Times • Mar. 22, 2026

When county clerk Brianna Lennon got an email in November saying a newly expanded federal system had flagged 74 people on the county’s voter roll as potential noncitizens, she was taken aback.

From Salon • Feb. 27, 2026

The chorus of boos that greets Mr. Horner clearly takes him aback, as it does the drivers shown backstage.

From The Wall Street Journal • Feb. 25, 2026

Byerley was taken aback, “Why do you say that?—I was rather hoping for your approval in this matter.”

From "I, Robot" by Isaac Asimov