Additional

5 clues
Extra
Supplementary
Not full member
Not on the floor model, say
Optional's meaning, in car pricing
Similar answers:
Addit
Addition
Additional
Additionalfood
Additionalmoney
Additionaltaxes
Additionbysubtraction
Additions
Additionto
Additive
Additives
Additory
Adhesional
Antinationalist
Augustanational
Chainaddition
Clothesoptional
Conational
Confessionalcourtesy
Congressionalidea