trying to achieve something that is not possible or practical.

He wanted to go into show business, but friends told him to quit chasing rainbows.

• with bare hands
• with bated breath
• with bells on
• with both barrels
• with brass knobs on
• with child
• wither on the vine
• with eyes closed
• with eyes open
• with eyes wide open
• with flying colors
• With friends like that, who needs enemies?
• with good reason
• with guns blazing
• with half an eye on
• with half an eye on someone
• with half an eye on something
• with ... hat on
• with hat on
• with head in the clouds
• within an inch of its life
• within an inch of life
• within an inch of your life
• within a whisker of
• within a whisker of something