When the sight of a person or thing brings back a vague memory and/or feeling of a dream you had the previous night. More likely than not, the person experiencing the dreamja vu cannot remember any additional details of the dream, creating a deja vu
-like feeling of "can't put my finger on it, but I remember it." Often causes interactions with the person or thing to take on a surreal feeling for the person experiencing dreamja vu.
This is not to be confused with suddenly remembering the entirety of a dream or a dream coming true.
Person 1: "Oh hey, Jennifer! ... Whoa, dreamja vu."
Person 2: "What?"
Person 1: "Oh, I think I had a dream about you last night."
Person 2: "What happened in it?"
Person 1: "No clue."