Adjective or noun ?

Hello,

My question concerns the word "relative" in the following sentence :
"Your collaborators' relative lack of experience may be a problem"

I think that "relative" is used here as attributive adjective of the noun "lack". But my colleague is not of my opinion. For him, "relative" used here is a noun which completes "experience", something in the kind of "cooperation experience".

Thank you for your helps,
Ansv

[Tdol]

I agree with you- it modifies the 'lack', to show that it is a lack in contrast to others' experience.