daydream (EN)
verb, noun

verb “daydream”

daydream; he daydreams; past daydreamed, daydreamt, part. daydreamed, daydreamt; ger. daydreaming
  1. to engage in the activity of having a stream of unrelated thoughts while awake
    During the long lecture, Sarah daydreamed about her upcoming vacation to the beach.

noun “daydream”

sg. daydream, pl. daydreams
  1. a stream of thoughts that occur when one is awake not related to what is currently happening
    During the boring lecture, Sarah slipped into a daydream about her upcoming beach vacation.