Stand-up person? (6)
'stand-up person' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for mensch that I've seen before include "Brick, US-style" , "Decent chap" , "Decent guy" , "Decent person" .)
(Another definition for noshow that I've seen is " One fails to attend".)