From Longman Dictionary of Contemporary Englishfrighten somebody/something ↔ off phrasal verbLEAVE A PLACEto make a person or animal so nervous or afraid that they go away or do not do something they were going to do The investors were frightened off by the company’s low profits that year. → frighten→ See Verb table
Examples from the Corpus
frighten off• Also, the ghosts of the carvers frightened me off.• I couldn't let him know the strength of my feelings - I was afraid it might frighten him off.• She was going out with a friend of mine, but she came on so strong that she frightened him off.• They wanted to talk to you direct, but I said that would frighten you off.• You're right to tread carefully, as if you do say anything to him you might well frighten him off!• I was very frightened of falling off the edge of the table, which was ten metres from the ground. 