The most common and most likely answer to this crossword clue is the 5 letter word STAND
I've seen this crossword clue in The Sunday Telegraph
S
T
A
N
D
More clues leading to the result STAND
Buddy explains!

The straight part
We know that "joker" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case joker = stand.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 STAND mean?
STAND noun- The act of standing.
- A defensive position or effort.
- A resolute, unwavering position; firm opinion; action for a purpose in the face of opposition.
- A period of performance in a given location or venue.
- A device to hold something upright or aloft.
- The platform on which a witness testifies in court; the witness stand or witness box.
- A particular grove or other group of trees or shrubs.
- A contiguous group of trees sufficiently uniform in age-class distribution, composition, and structure, and growing on a site of sufficiently uniform quality, to be a distinguishable unit.
- A standstill, a motionless state, as of someone confused, or a hunting dog who has found game.
- A small building, booth, or stage, as in a bandstand or hamburger stand.
- A designated spot where someone or something may stand or wait.
- The situation of a shop, store, hotel, etc.
- Grandstand. (often in the plural)
- A partnership.
- (plural often stand) A single set, as of arms.
- Rank; post; station; standing.
- A state of perplexity or embarrassment.
- A young tree, usually reserved when other trees are cut; also, a tree growing or standing upon its own root, in distinction from one produced from a scion set in a stock, either of the same or another kind of tree.
- A weight of from two hundred and fifty to three hundred pounds, used in weighing pitch.
- A location or position where one may stand.
- (heading) To position or be positioned physically.
- (heading) To position or be positioned mentally.
- (heading) To position or be positioned socially.
- Of a ship or its captain, to steer, sail (in a specified direction, for a specified destination etc.).
- To remain without ruin or injury.
- To stop asking for more cards; to keep one's hand as it has been dealt so far.