The Roman Map of Britain Mag(io)louento Dropshort, Little Brickhill, Buckinghamshire

Magiovinto (AI 471₁ Iter II)
Magiovinio (AI 476₁₀ Iter vi)
Magiovinio (AI 479₆ Iter viii)

    Magiovinio (PNRB Magiovinium) has long been considered the proper form and the derivation remained obscure. Dropshort is located on the River Ouzel, alternatively known as the Lovat. Early forms of Lovat are Lovente ca. 1200 and Lavente, Louette, Luuente 1276.  The Lavant of Sussex is considered identical. 
    I propose that the proper form of the place-name known as Magiovinio incorporates the river-name Lovento or Lovinto as the second element.  
    Mag- or Magio- is magus 'river plain'. Nothing regarding the size of the town or river suggests magio 'great'. If Magio- is correct, then the source map was in error, the map-maker guilty of an eye-skip (io for iolo). If Mag- is correct, then perhaps it is a separate word - Mag Louento - as I would expect a compositional vowel.

Dropshort SP8833

    OW magu 'nourish' has some potential,  see Maglone.