ON- (A.S.), on, as _on_set, _on_looker. [See _On_ in Dict.]

OP-, as in _op_press. See Ob-.

OR- (A.S.), out, in _or_deal. [A.S. _or-_; cog. with Dut. _oor-_, Ger.

_ur-_, Goth, _us-_, away, out of.]

OS-, as in _os_tensible. See Ob-.

OUT- (A.S.), out, beyond, as _out_law, _out_bid, _out_side, _out_cast.

[A.S. _út_.]