Short film with old man, mathematician Blaise (6)
I believe the answer is:
pascal
'mathematician blaise' is the definition.
(I've seen this in another clue)
'short film with old man' is the wordplay.
I cannot really understand how this works, but
'man' could be 'cal' and 'cal' is found in the answer.
The remaining letters 'pas' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for pascal that I've seen before include "17th century French mathematician -- SI unit of pressure" , "clever thinker" , "religious philosopher" , "Unit of pressure; French scientist" , "French mathematician, d. 1662 - SI unit of pressure" .)