Start at one, working to produce primer (10)
I believe the answer is:
foundation
'primer' is the definition.
(type of make-up)
'start at one working' is the wordplay.
'start' becomes 'found' (I've seen this before).
'one' becomes 'i' (roman numeral).
'working' becomes 'on'.
'found'+'at'+'i'+'on'='FOUNDATION'
'to produce' is the link.
(Other definitions for foundation that I've seen before include "Artificial jet of water" , "Underlying basis" , "cosmetic aid?" , "charity, say" , "Base" .)