The most common and most likely answer to this crossword clue is the 5 letter word TILES
I've seen this crossword clue in The Daily Telegraph
T
I
L
E
S
More clues leading to the result TILES
Buddy explains!
The straight part
We know that "Hats" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case hats = tiles.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 TILES mean?
TILES noun- A regularly-shaped slab of clay or other material, affixed to cover or decorate a surface, as in a roof-tile, glazed tile, stove tile, carpet tile etc.
- A rectangular graphic.
- Any of various flat cuboid playing pieces used in certain games, such as dominoes, Scrabble, or mahjong.
- A stiff hat.
- To cover with tiles.
- To arrange in a regular pattern, with adjoining edges (applied to tile-like objects, graphics, windows in a computer interface).
- To optimize (a loop in program code) by means of the tiling technique.
- To protect from the intrusion of the uninitiated.