The most common and most likely answer to this crossword clue is the 5 letter word SHALE
I've seen this crossword clue in The Daily Telegraph
S
H
A
L
E
More clues leading to the result SHALE
- Introduction of secure, healthy, source of gas
- Sunflower’s head — healthy source of oil
- Say nothing, given drink that may be full of gas!
- Singular, healthy, variety of gas
- Source of gas market includes hydrogen
- Rock hotel in auction
- Small, strong rock
- Spain's premier healthy oil producer
- Quiet beer possibly source of gas
Buddy explains!
The straight part
We know that "possibly source of gas (5)" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case possibly source of gas (5) = shale.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 SHALE mean?
SHALE noun- A shell or husk; a cod or pod.
- A fine-grained sedimentary rock of a thin, laminated, and often friable, structure.
- To take off the shell or coat of.