Nobody agrees on where the name Carugate comes from. The proposals include carrucata, the land a peasant can work with a pair of oxen; carrivium, the cart road; callugate, misty ground; el caraga, a vine pest; and carugol, the tool used to thresh grain. The boundaries are odd too: the village belonged to the Vimercatese, but in 2004 it was the only one there not to join the new province of Monza e Brianza, and stayed with Milan.
Tradition has it that Saint Marcellina, sister of Ambrose and Satyrus, consecrated on Christmas night, lived here, and that the house where she withdrew to pray with her companions became the Benedictine monastery recorded in a document of 1398; she is still celebrated alongside the patron Saint Andrew. The coat of arms is an archive of families: the gold and red bends come from the de Gallarane, the castle perhaps from the gate of the Giulini della Porta, their heirs, and the two pines from the Silva, a branch of whom died out into the Ghirlanda, large landowners here.