The Roman Map of Britain Abus River Ouse?

Abou potamou ekbola Abus (Ptolemy II 3 4)

    If Gabrantovicum (for Tarrantonicum) represents the Trent, then the assignment of Abus to the Humber needs reconsideration. The position and availability of a relatable name point to Ouse as Ptolemy's Abus.
    The root of Abus appears to be Celtic *ab- 'river', as in Abona. According to Ekwall the Great Ouse, (on) Usan 880, would have the normal OE form Use and a short form Us, oblique Use. He derives Ouse from the base *udso which would result in a Welsh *ws with subsequent vowel lengthening.
    Consider McBain: Ab - the river Ow in the barony of Ballinacor (Ireland). Watson p477 : Abhain Abha, the river Awe; and the Lochs Awe of Sutherland Loch Obha and Loch Abha.