Pillar of America consumed by boasting (8)
I believe the answer is:
baluster
'pillar' is the definition.
(I've seen this before)
'america consumed by boasting' is the wordplay.
'america' becomes 'a' (common abbreviation - e.g. in organisation names).
'consumed by' indicates putting letters inside.
'boasting' becomes 'bluster' (bluster is a kind of boasting).
'a' going inside 'bluster' is 'BALUSTER'.
'of' acts as a link.
(Other definitions for baluster that I've seen before include "pillar of support" , "One of a number of closely spaced supports for a railing" , "post" , "Set of posts supporting a rail" , "Pillar supporting staircase rail" .)