The most common and most likely answer to this crossword clue is the 7 letter word ELEMENT
I've seen this crossword clue in Independent
E
L
E
M
E
N
T
More clues leading to the result ELEMENT
- Possibly copper’s sphere of operation
- He's one to have English mild sans head
- European allowed to conceal crew's hint
- Iron perhaps used for cores to help cements?
- Oxygen, for example, just a hint?
- Something in a kettle — hydrogen or oxygen, perhaps?
- Soldiers in East allowed to fire, perhaps, once
- Essence of chess: to sanction capturing pieces? That’s the essential part
- Fire, for example, in electrical component?
- Some clientele mentioned what is essential to them
Buddy explains!

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 ELEMENT mean?
ELEMENT noun- One of the simplest or essential parts or principles of which anything consists, or upon which the constitution or fundamental powers of anything are based.
- A small part of the whole.
- The sky.
- (with "the") Atmospheric forces such as strong winds and rains.
- A place or state of being that an individual or object is best suited to.
- (usually in the plural) The bread and wine taken at Holy Communion.
- A group of people within a larger group having a particular common characteristic.
- A component in electrical equipment, often in the form of a coil, having a high resistance, thereby generating heat when a current is passed through it.
- One of the conceptual objects in a markup language, usually represented in text by tags.
- To compound of elements.
- To constitute and be the elements of.