1) From Old French <i>naperon</i>, a diminutive of <i>nape</i> meaning table-cloth.
The initial ‘n’ was lost in ‘a napron’. It had a variety of spellings which may indicate how it was pronounced: 1556 one harden sheitt, one cou[er]let, one apperone, Beeston
1615 one grene apparone, iij patlets, Keighley
1638 fower aperance, one of fembel, three of harden, Thorpe Willoughby.