Weeps about the mistaken conclusion of pretentious persons (5)
I believe the answer is:
snobs
'pretentious persons' is the definition.
(I've seen this before)
'weeps about the mistaken conclusion' is the wordplay.
'weeps' becomes 'sobs' (sobbing is a kind of weeping).
'about' indicates putting letters inside.
'conclusion' says to take the final letters.
The final letter of 'mistaken' is 'n'.
'sobs' going around 'n' is 'SNOBS'.
'of' is the link.
(Other definitions for snobs that I've seen before include "have jobs at last" , "Pretentious persons" .)