The most common and most likely answer to this crossword clue is the 4 letter word ETNA
E
T
N
A
More clues leading to the result ETNA
- Some returned from enchanted mountain
- Volcano located in Tibet, naturally
- Greek character goes around northern volcano
- Some sweet nature, but it is liable to erupt
- Initially erupting, this naturally active volcano
- Return stake that’s hotly tipped in Sicily
- Volcano: bet goes up
- Pay up for heater
- Greek character describing northern volcano
- Vessel’s partially wet, naturally
Buddy explains!

The straight part
We know that "I’m still active" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case i’m still active = etna.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.