Wiktionary
n. A small blue butterfly, (taxlink Polyommatus icarus species noshow=1), of the family Lycaenidae
Wikipedia
The common blue, Polyommatus icarus, is a small butterfly in the family Lycaenidae, widespread over much of the Palaearctic in temperate Asia and Europe.
It is a recently introduced species in eastern Canada.
Usage examples of "common blue".
He was completely unaware that his wounded mitt hung so tantalizingly in the water, just as he was unaware of the cannibalistic proclivities of Callinectes sapidus, the common blue crab.
The common blue tit is loved by everyone until it steals the cream off the milk.
Vickers' theory was that, if he went back in the common blue overall, it would help confuse surveillance systems.
She wore the common blue tunic and trousers, zori on bare feet, fireburst tattoo on the arm which slid from its sleeve as she offered her hand.
Her eyes were a common blue, neither pale nor particularly colorful.