Some dirigibles, you may see, are quite different from a blimp (5)
I believe the answer is:
rigid
'some' is the definition.
Both the answer and definition are adjectives. Perhaps they are linked in a way I don't understand?
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for rigid that I've seen before include "Stiff, unbending" , "starched too much?" , "completely" , "not relaxing" , "Stiff, unyielding" .)