The most common and most likely answer to this crossword clue is the 7 letter word SURREAL
I've seen this crossword clue in The Guardian
S
U
R
R
E
A
L
More clues leading to the result SURREAL
- Most of certain area offloading millions of unusual paintings?
- Bizarre reduction in area around Woking — completely reduced
- Bizarre sport going up river disturbs aquatic mammal
- Fantastic laser playing over old city
- Bizarre posh and expensive car covered in cork
- Almost certainly genuine – that’s bizarre
- Stop circling source of Ugandan rivers ? it’s bizarre!
- County doesn’t finish a league? That’s weird
- A ruler’s confused in a dream world
- United, king and queen stamp about — bizarre
Buddy explains!

The straight part
We know that "in a dream world" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case in a dream world = surreal.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SURREAL mean?
SURREAL noun- Surreal number
- Resembling a dream: fantastic and incongruous