Idioms are phrases which cannot be understood simply by looking at the meaning of the individual words in the phrase.
stars in one's eyes
to have an appearance or feeling of very great happiness
The woman had stars in her eyes when she saw the beautiful ring that her boyfriend gave her.
List of common idioms, their meanings and examples of their usage in sentences
An idiom is defined as - a group of words in a fixed order that has a particular meaning that is different from the meanings of each word on its own.