The most common and most likely answer to this crossword clue is the 5 letter word GRATE
I've seen this crossword clue in The Times
G
R
A
T
E
More clues leading to the result GRATE
- Reportedly big jar
- To have an irritating effect can be wicked, we hear
- Fantastic-sounding place to light a fire!
- Jar smashing by the sound of it
- Wicket restricting runs making one fret
- Super-sounding grid
- Old snake may be in this cage
- One may be under fire, seeing price put on gallon
- Jar that may contain ashes
- Jar‘s good value
Buddy explains!

The straight part
We know that "jar" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case jar = grate.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 GRATE mean?
GRATE noun- A horizontal metal grill through which water, ash, or small objects can fall, while larger objects cannot
- A frame or bed, or kind of basket, of iron bars, for holding fuel while burning
- To furnish with grates; to protect with a grating or crossbars
- To shred (things, usually foodstuffs), by rubbing across a grater
- To make an unpleasant rasping sound, often as the result of rubbing against something
- (by extension) to get on one's nerves; to irritate, annoy
- (by extension) to annoy
- Serving to gratify; agreeable.
- Relatively large in scale, size, extent, number (i.e. having many parts or members) or duration (i.e. relatively long); very big.
- Of larger size or more importance than others of its kind.
- (qualifying nouns of family relationship) Involving more generations than the qualified word implies — as many extra generations as repetitions of the word great (from 1510s). [see Derived terms]
- (followed by 'with') Pregnant; large with young; full of.
- (except with 'friend' and similar words such as 'mate','buddy') Intimate; familiar.
- Extreme or more than usual.
- Of significant importance or consequence; important.
- (applied to actions, thoughts and feelings) Arising from or possessing idealism; admirable; superior; commanding; heroic; illustrious; eminent.
- Impressive or striking.
- Much in use; favoured.
- (applied to persons) Endowed with extraordinary powers; of exceptional talents or achievements; uncommonly gifted; able to accomplish vast results; remarkable; strong; powerful; mighty; noble.
- Title referring to an important leader.
- Doing or exemplifying (a characteristic or pursuit) on a large scale; active or enthusiastic.
- (often followed by 'at') Skilful or adroit.
- Very good; excellent; wonderful; fantastic (from 1848).
- Intensifying a word or expression, used in mild oaths.