To be in a dazed, semiconscious, crazy, or love-stricken state. Believed to be caused by a phase of the moon.
"Ted sure looked moonstruck after he drove his new lamborghini around the block."
a phenomenon of a stupid man who totally loses his mind and starts acting dumb whenever he sees hot chicks. even a man of ability falls into this category. so almost every man is a moonstruck dog.
he acts like a moonstruck calf on chicks.