I think it's been suggested that with the plural definite article nA, nA-itrw > *nA-ya3re etc. > neilos/nilus/Nile.
There's a Biblical passage in Exodus with three Egyptian loanwords almost in a row, something like: Moses (Mosheh, an Egyptian name) lifted his staff (matteh, Egyptian mdw) over the river/Nile (ye3or).