[Extra love]

How does oxidation of a molecule occur without oxygen?

[Kryolith]

"Oxidation describes the loss of electrons by a molecule, atom or ion"

You need a reactan that is "willing" to accept electrons (and thus being reduced)

http://en.wikipedia.org/wiki/Redox

[Arkcon]

How does oxidation of a molecule occur without oxygen?

Simple.  The definition of oxidation was changed, without changing the name.  It used to mean the reaction of oxygen with free metal.  It was changed to mean transfer of electrons from any source to another source, like Kryolith said.  Lots of terms used by people named Lavoisier and the like, did not survive the centuries unchanged.

[Extra love]

How does oxidation of a molecule occur without oxygen?

Simple.  The definition of oxidation was changed, without changing the name.  It used to mean the reaction of oxygen with free metal.  It was changed to mean transfer of electrons from any source to another source, like Kryolith said.  Lots of terms used by people named Lavoisier and the like, did not survive the centuries unchanged.

I didn't get what you mean.

[Sev]

Consider rxn: Cu⁰ + 2Ag⁺ → Cu²⁺ + 2Ag⁰

Cu has lost e^-s - it has been oxidised.