The most common and most likely answer to this crossword clue is the 5 letter word BOOTS
I've seen this crossword clue in Financial Times
B
O
O
T
S
More clues leading to the result BOOTS
Buddy explains!

The straight part
We know that "footwear/a drug dealer?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case footwear/a drug dealer? = boots.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 BOOTS mean?
BOOTS noun- A heavy shoe that covers part of the leg.
- A blow with the foot; a kick.
- A flexible cover of rubber or plastic, which may be preformed to a particular shape and used to protect a shaft, lever, switch, or opening from dust, dirt, moisture, etc.
- (usually preceded by definite article) A torture device used on the feet or legs, such as a Spanish boot.
- A parking enforcement device used to immobilize a car until it can be towed or a fine is paid; a wheel clamp.
- A rubber bladder on the leading edge of an aircraft’s wing, which is inflated periodically to remove ice buildup. A deicing boot.
- A place at the side of a coach, where attendants rode; also, a low outside place before and behind the body of the coach.
- A place for baggage at either end of an old-fashioned stagecoach.
- (police) A recently arrived recruit; a rookie.
- The luggage storage compartment of a sedan or saloon car.
- The act or process of removing or firing someone (give someone the boot).
- Unattractive person, ugly woman (usually as "old boot")
- A hard plastic case for a long firearm, typically moulded to the shape of the gun and intended for use in a vehicle.
- A bobbled ball.
- The inflated flag leaf sheath of a wheat plant.
- To kick.
- To put boots on, especially for riding.
- To apply corporal punishment (compare slippering).
- To forcibly eject.
- To disconnect forcibly; to eject from an online service, conversation, etc.
- To vomit.
- (criminal slang) To shoot, to kill by gunfire.
- Remedy, amends.
- Profit, plunder.
- That which is given to make an exchange equal, or to make up for the deficiency of value in one of the things exchanged; compensation; recompense.
- Profit; gain; advantage; use.
- Repair work; the act of fixing structures or buildings.
- A medicinal cure or remedy.
- To avail, benefit, profit.
- To benefit, to enrich; to give in addition.
- The act or process of bootstrapping; the starting or re-starting of a computing device.
- To bootstrap; to start a system, e.g. a computer, by invoking its boot process or bootstrap.
- A bootleg recording.
- A servant at a hotel etc. who cleans and blacks the boots and shoes.