C1idiominformalnature
a snake in the grass
USUK
a person who seems friendly but secretly cannot be trusted
It is a strong insult, so use it about people you know well. It is stronger than 'a bad friend'.
In context
Be careful with Tuan: he smiles at you, but he is a snake in the grass.
I trusted her with my secret, but she turned out to be a snake in the grass.
More idioms about nature
- a big fish in a small pondan important person, but only in a small group or place
- a bird's-eye viewa view of something from high above
- a breath of fresh airsomeone or something new and different that makes a situation more pleasant
- a dark horsea person with hidden talents, or a competitor nobody expected to do well
- a drop in the oceana very small amount compared with what is needed