1. a letter, an exchange of letters

“Our correspondences have wings - paper birds that fly from my house to yours - flocks of ideas crisscrossing the country."

- Terry Tempest Williams (1955 - )

2. similarity, equivalence, connection

“In the motion of the very leaves of spring, in the blue air, there is then found a secret correspondence with our heart.”

- Percy Bysshe Shelley (1792 - 1822)