On thin ice — In a risky or precarious situation where one more mistake could lead to serious consequences. If you are on thin ice, you are dangerously close to causing a major problem or losing someone's trust, patience, or goodwill.
Origin & History
The phrase comes from the very real danger of walking or skating on ice that is not thick enough to hold a person's weight. In colder climates before the age of indoor skating rinks, venturing onto frozen lakes and rivers was a common winter activity — and a potentially fatal one if the ice was too thin.
By the mid-19th century, writers and speakers began using the image figuratively to describe socially or professionally precarious situations. The connection is intuitive: just as a crack in the ice could mean disaster, so one more wrong move in a delicate human situation can cause everything to fall through.
Example Sentences
| Sentence | Context |
|---|---|
| After being late three times, she was on thin ice with her manager. | Workplace / professional |
| The politician was on thin ice after the leaked memo contradicted his public statement. | Politics / media |
| He knew he was on thin ice when he forgot their anniversary for the second year in a row. | Personal relationship |
| The student was already on thin ice before she missed the deadline for the final assignment. | Academic context |
| The company is on thin ice financially — one more bad quarter could end everything. | Business / finance |
How to Use It
Use on thin ice to describe a person or organisation that is in a fragile, high-risk position — one where any further mistake will lead to a serious outcome such as being fired, a relationship breaking down, or a project collapsing. The idiom focuses on the nearness of disaster, not simply the presence of risk.
It is most natural in spoken English and informal writing. You can use it in the present tense ("she is on thin ice"), the past tense ("he was on thin ice"), or conditionally ("if you do that, you'll be on thin ice").
Conversation example:
A: "Did Tom get a warning from HR again?"
B: "Yes — he's really on thin ice now. One more complaint and they'll let him go."
Another example:
A: "Should I ask for another extension on the project?"
B: "I wouldn't. You're already on thin ice with the client after the last delay."
Common Mistakes
Mistakes to Avoid
She is on a thin ice with her boss.
She is on thin ice with her boss. — No article before "thin ice"; this is a fixed phrase.
The weather forecast is on thin ice. — (wrong context: the idiom needs a human or organisation in a risky social/professional situation)
The project team is on thin ice after missing two deadlines. — Applies to people or groups facing real consequences.
I put him on thin ice by giving him a second chance.
Giving him a second chance put him on thin ice with the rest of the team. — You cannot intentionally "put" someone on thin ice as a positive act; the phrase implies the person's own behaviour has created the risk.
Related Idioms
Practise This Idiom
Practice English Idioms
Use these exercises to master idioms in context: