An allusion to the belief that the moon causes mental instability.
1. To be overcome with romantic feelings or sentiments. Don't listen to Betty—she's just moonstruck and wants everyone to be in love along with her.
2. To be crazy or deranged. I'll be moonstruck if I have to deal with these screaming toddlers for much longer. My family thinks I'm moonstruck just because I practice a form of alternative medicine using magnetic fields.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.