The most common and most likely answer to this crossword clue is the 6 letter word FLARED
F
L
A
R
E
D
Buddy explains!

The straight part
We know that "wide at the bottom" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case wide at the bottom = flared.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 FLARED mean?
FLARED verb- To cause to burn.
- To cause inflammation; to inflame.
- To open outward in shape.
- To (operate an aircraft to) transition from downward flight to level flight just before landing.
- To blaze brightly.
- To shine out with a sudden and unsteady light; to emit a dazzling or painfully bright light.
- To shine out with gaudy colours; to be offensively bright or showy.
- To suddenly happen or intensify.
- To suddenly erupt in anger.
- To be exposed to too much light.