Low point for some in a dirigible (5)
I believe the answer is:
nadir
'low point' is the definition.
(I've seen this before)
'some in a dirigible' is the wordplay.
'some' says the answer is hidden in the clue (some of the parts of the word are used).
'NADIR' can be found hidden inside 'in a dirigible'.
'for' acts as a link.
(Other definitions for nadir that I've seen before include "businessman formerly escaping justice" , "pits" , "Lowest point, or time of deepest depression." , "deep despair" , "Given lowest place" .)