Correct Answer: Someone who lacks courage and is easily frightened

Solution : The correct choice is the fourth option .

The idiom chicken hearted is used to describe an individual who is easily frightened, timid, or lacks courage. It likens the person to a chicken, which is often associated with being fearful or easily scared.

Therefore, among the given options, the appropriate meaning of the given idiomatic expression is, someone who lacks courage and is easily frightened.