During March, say, removed oil from pillar (8)
I believe the answer is:
monolith
'pillar' is the definition.
(I have seen 'Big pillar' mean 'monolith' so perhaps 'pillar' could also mean 'monolith')
'during march say removed oil' is the wordplay.
'during' is an insertion indicator.
'march say' becomes 'month' (march is a kind of month**).
'removed' is an anagram indicator (moved again).
'oil' is an anagram of 'oli'.
'month' going around 'oli' is 'MONOLITH'.
'from' acts as a link.
(Other definitions for monolith that I've seen before include "Monument of a large standing stone" , "Stone pillar" , "Statue from one block of stone" , "Pillar-like stone" , "Single great stone, column or obelisk say" .)