Take ___ (give pause)

• Surprising way to be taken
• Taken __: disconcerted
• Taken __ (startled)
• Flattened, as sails against the mast
• Surprised (with "taken")
• One is surprised when taken thus
• Taken -- (caught by surprise)

WordNet Word definitions in WordNet
adv: having the wind against the forward side of the sails; "the ship came up into the wind with all yards aback" by surprise; "taken aback by the caustic remarks"

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Aback \Ab"ack\ ([a^]b"ak), n. An abacus. [Obs.] --B. Jonson.

Wikipedia Word definitions in Wikipedia