Protection:
* Shield
* Safeguard
* Protect
* Defend
* Conceal
Concealment:
* Hide
* Mask
* Disguise
* Veil
* Cloak
Surface:
* Surface
* Exterior
* Facade
* Skin
* Wrapper
Encompass:
* Include
* Embrace
* Enclose
* Contain
* Span
Financial:
* Pay
* Compensate
* Indemnify
* Guarantee
* Insure
Musical:
* Version
* Adaptation
* Rendition
* Interpretation
* Arrangement
Please provide more context about how you are using "cover" so I can give you a more accurate synonym.