Humiliated by article on Foundation Day (6)
I believe the answer is:
abased
'humiliated' is the definition.
('abase' can be a synonym of 'humiliate')
'article on foundation day' is the wordplay.
'article' becomes 'a' (indefinite article).
'on' says to put letters next to each other.
'foundation' becomes 'base' ('base' can be a synonym of 'foundation').
'day' becomes 'd'.
'a'+'base'+'d'='ABASED'
'by' acts as a link.
(Other definitions for abased that I've seen before include "Humiliated or degraded" , "Demeaned (oneself)" , "Disgraced" , "Belittled, degraded" , "Humbled, mortified" .)