roddonn.

Etymology: Origin uncertain. Perhaps the reflex of a Middle English compound < road n. + holm n.¹ (compare holm n.¹ 2a and 3, both of which frequently occur in place names), the silt banks being so called on account of their suitability as thoroughfares, since they are long, narrow, and raised above the ground, and drain easily in relation to the peat fen through which they run. See further R. Coates in Notes & Queries (2005) June 170–2. If so, the first element could show late Middle English or early modern English shortening of open ō before d (compare E. J. Dobson Eng. Pronunc. 1500–1700 (ed. 2, 1968) II. §33); compare also rare short-vowel forms at road n. As regards the second element, Coates notes that holm n.¹ frequently occurs in reduced forms in place names especially in coastal areas of Lincolnshire (where it appears as -ham, -am, -um, etc.).The spelling roddon was adopted and popularized by G. Fowler (see quot. 1932), and predominates in technical discussions, whilst the older form in -ham remains dominant in local use. Contrary to the opinion expressed in the following quot., any etymological connection with roddin n. is unlikely, as the two words show very different geographical distributions:1932 G. Fowler in Geogr. Jrnl. 79 210 There are numerous raised banks of laminated silt or shell maul meandering through the Fens. Neither historians nor geologists appear to have noticed them... Fen dwellers however have noted these banks but generally without realizing their origin. They call them roddons. This word appears to be allied to roddin or rodden, which Wright in his ‘English Dialect Dictionary’..gives as meaning a narrow road, path or sheep track. I spell the word roddon as it sounds; and I prefer it as a spelling to rodham, as used in the name Rodham Farm, as the latter appears corrupted in the second syllable. Also attested in the Cambridgeshire place names Rodham Farm , Rodham Drove (both 19th cent.; compare quot. 1932 above).