Gigantic insect covering a tiny distance (7)
I believe the answer is:
mammoth
'gigantic' is the definition.
(I know that gigantic can be written as mammoth)
'insect covering a tiny distance' is the wordplay.
I cannot quite see how this works, but
'insect' could be 'moth' (moth is a kind of insect) and 'moth' is found in the answer.
'a' is within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for mammoth that I've seen before include "Large extinct elephant" , "Extinct woolly creature" , "Huge" , "Large extinct beast" , "Immense" .)