The most common and most likely answer to this crossword clue is the 6 letter word GASPED
G
A
S
P
E
D
Buddy explains!

The straight part
We know that "Panted" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case panted = gasped.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 GASPED mean?
GASPED verb- To draw in the breath suddenly, as if from a shock.
- To breathe laboriously or convulsively.
- To speak in a breathless manner.
- To pant with eagerness; to show vehement desire.