Timid person ignoring son's pout (4)
I believe the answer is:
moue
'pout' is the definition.
('moue' can be a synonym of 'pout')
'timid person ignoring son's' is the wordplay.
'timid person' becomes 'mouse'.
'ignoring' is a deletion indicator.
'mouse' with 's' taken out is 'MOUE'.
(Other definitions for moue that I've seen before include "Disdainful pout" , "Insolent pout" , "Expression of disdain" , "Face" , "expression of displeasure" .)