What does it mean to "raise eyebrows"?

To raise eyebrows means to cause other people to react with surprise or mild disapproval. To raise an/your eyebrow means to move your eyebrows up in a way that shows surprise or mild disapproval.

Both of these phrases are often used figuratively. The following example sentences show how each phrased is used.

To raise eyebrows

• Her sudden outburst in class raised eyebrows. [=classmates reacted with surprise or mild disapproval to her outburst]
• He raised eyebrows when he walked down the street in a winter coat during summer. [=people were surprised to see him in clothing that was not appropriate for the weather]
• The band's new album is raising eyebrows [=causing people to act with surprise or disapproval] with its shocking lyrics.
• The scandal raised eyebrows [=caused surprise and/or disapproval] all over town.

To raise an/your eyebrow

• He raised an eyebrow at his mother when she bought a sports car. [=he was surprised that his mother bought a sports car]
• The townspeople raised their eyebrows at the new strict laws. [=they felt disapproval towards the new laws]
• No one raised an eyebrow [=no one was surprised] when he quit his job; he never liked it anyway.
• Her brother raised an eyebrow [=he expressed surprise and/or disapproval] when she told him she was moving to Los Angeles to pursue acting.