The most common and most likely answer to this crossword clue is the 6 letter word RENDER
I've seen this crossword clue in The Daily Telegraph
R
E
N
D
E
R
More clues leading to the result RENDER
- Represent someone who tears coat on wall
- Melt tip and root of eggplant stuffed into razor shell
- Make plaster
- Reminder — note not included in present
- About right checking finish for plaster
- Perform Shylock perhaps, right to take pound
- Give back Santa’s helper that is broken and lost inside
- Give up and put a coat on before decorating
- Give up with plaster
- Deliver a coat
Buddy explains!

The straight part
We know that "plaster" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case plaster = render.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 RENDER mean?
RENDER noun- Stucco or plaster applied to walls (mostly to outside masonry walls).
- A digital image produced by rendering a model.
- A surrender.
- A return; a payment of rent.
- An account given; a statement.
- (ditransitive) To cause to become.
- To interpret, give an interpretation or rendition of.
- To translate into another language.
- To pass down.
- To make over as a return.
- To give; to give back; to deliver.
- To give up; to yield; to surrender.
- To transform (a model) into a display on the screen or other media.
- To capture and turn over to another country secretly and extrajudicially.
- To convert waste animal tissue into a usable byproduct.
- To have fat drip off meat from cooking.
- To cover a wall with a layer of plaster.
- To pass; to run; said of the passage of a rope through a block, eyelet, etc.
- To yield or give way.
- To return; to pay back; to restore.
- To inflict, as a retribution; to requite.
- One who rends.