I've heard contravariant functors referred to as "cofunctors", and I've also heard objections to that term.  As I'm preparing to release some libraries using contravariant functors, I'd appreciate hearing preferences and/or reasons.  For instance, another name would be "Contrafunctor".

-- | Contravariant functors.  often useful for /acceptors/ (consumers,
-- sinks) of values.
class Cofunctor acc where
  cofmap :: (a -> b) -> (acc b -> acc a)

Thanks,  - Conal