What it means
When something sets alarm bells ringing, it triggers an instant sense that something is wrong, a warning that rings out in your head the way an alarm clangs through a building. You hear alarm bells when a deal sounds too good, a story does not add up or someone acts oddly. It is the gut-level signal to pay attention and be wary before going any further.
Usage examples
"Something about the offer set alarm bells ringing straight away."
"The moment he asked for the money upfront, alarm bells started ringing."
"When he asked for the deposit in cash, alarm bells started ringing straight away."
"Her story kept changing, and that set off a few alarm bells for me."
Where it comes from
A transparent picture from real alarm bells: the moment they start ringing everyone knows something is wrong. The phrase carries that warning over to any sign that makes you suddenly suspicious or worried.
Other ways to say it
Editors of this term
Your vote counts
Is this real street talk or have we lost the plot? Cast your vote.