The most common and most likely answer to this crossword clue is the 7 letter word METHANE
M
E
T
H
A
N
E
More clues leading to the result METHANE
- Greenhouse gas meant he worried
- Cows produce it: change the name
- Gas will give shivering men heat
- Neo with feudal lord in flammable gas
- Change the name of a fuel
- Gas offered by this writer on Macbeth?
- Gas with Hoskins and another then start on alcohol
- Gas meter almost broken by workman…almost
- Neat production, as Macbeth himself might have admitted?
- Embarrassed men hate making gas
Buddy explains!

The straight part
We know that "gas" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case gas = methane.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 METHANE mean?
METHANE noun- The simplest aliphatic hydrocarbon, CH₄, being a constituent of natural gas, and one of the most abundant greenhouse gases.
- Any of very many derivatives of methane.