Hm, Ambroos is a tricky one. The best I could think of would be "arm" (assuming they're not with a rhotic-r accent, though I could imagine people then making it

Hm, Ambroos is a tricky one. The best I could think of would be "arm" (assuming they're not with a rhotic-r accent, though I could imagine people then making it sound like aam) + "close" (as in dichtbij, not sluiten.)