It’s funny: the feeling described by this word is one that is as common to the human experience as attachment itself, and yet only the Portuguese have a single word for it? How can this be?
Saudade describes a deep emotional state of nostalgic longing for an absent something or someone that one loves. It often carries a repressed knowledge that the object of longing will never return. It’s related to the feelings of longing, yearning.
Read more here.