ob-(Prefix)

Against; facing; a combining prefix found in verbs of Latin origin.

ob-(Prefix)

Of a reversed shape.

Ob-(u)

a prefix signifying to, toward, before, against, reversely, etc.; also, as a simple intensive; as in oblige, to bind to; obstacle, something standing before; object, lit., to throw against; obovate, reversely, ovate. Ob- is commonly assimilated before c, f, g, and p, to oc-, of-, og-, and op-