This is the 658th most frequent Turkish word.
rüyada
"In a dream."
Here, 'rüyada' is used to describe an action occurring within a dream.
Rüyada uçmak gibisi yok.
There is nothing like flying in a dream.
In this sentence, 'rüyada' refers to the events observed during a dream.
Rüyada gördüklerimi hatırlayamıyorum.
I cannot remember what I saw in the dream.
Here, 'rüyada' specifies the setting of the interaction as being within a dream.