荫凉 describes a place that is both shady and pleasantly cool, typically because of trees, buildings, or other structures blocking direct sunlight. It's a stative verb (s.v.) in Chinese, functioning like an adjective in English — you can say 这里很荫凉 ('it's shady and cool here'). Unlike 凉快 (cool and refreshing), 荫凉 specifically implies the shade is the cause of the coolness.