(1) 'redness'; (2) 'rottenness'(Modern English (2) rotten)
Two identifications have been proposed for this n. in Cl 1009 ('Suche a roþum of a reche ros fro þe blake'): (1) Almost all editors agree on the sense of this n. as 'redness' and derive it from ON. The precise etymon depends on whether the MS spelling at Cl 1009 is expanded as <roþun> or <roþum>; the form is unique either way. (a) If roþun, it is connected to the v. represented by OIcel roðna 'redden' (thus GollCl, followed by Olsen etc.; see further Bj. 15 on the borrowed v.). (b) If roþum (as Anderson prefers, followed by OED3), to the OIcel n. roþmi 'redness'. Both are formed within ON on PGmc *rod- (related to the st. v. *reudan- 'redden'; cp. the nouns OE rudu, OIcel roði, MLG rode 'redness' and the wv. *rudēn- represented by OIcel roða 'gleam red' and OHG rotēn 'turn red'). (2) Menner (followed by Vant) instead interprets it as a variant sb. form of the adj. rotun 'rotten', probably < ON, cp. the OIcel pp. rotinn used in this way, and indicating a st. v. *reutan- on which the various NGmc and WGmc wk. verbs are derived, cp. OE gerotian 'rot, putrefy', OFris rotia, MDu rotten, OS rotōn, OHG rozzēn, OIcel rotna. Cp. also rot (n.). Either interpretation is possible in the context of the line, but (1) provides a better fit as well as explanation of the form.
(1) *rod-; (2) *rut-
Proposed ON Etymon (OIcel representative)
(1a) roðna (v.) 'redden'; (1b) roþmi (n.) 'redness'; (2) rotinn (adj.) 'rotten'
(ONP (1a) roðna (vb.); (1b) roþmi (sb.); (2) rotinn (adj.))
Other Scandinavian Reflexes
(1a) Far rodna, Icel roðna, Norw rodna, Sw rodna, Sw dial rudna; (1b) Dan rødme, OSw rodme, rudhme; (2) Far rotin, Icel rotinn, Norw roten, Dan rådden, Sw rutten, Sw dial rotin
(2) cp. gerotian 'rot, putrefy'
Phonological and morphological markers
[ON fricative /ð/ < PGmc */ð/] (may not be applicable)
(1) hapax legomenon; (2) Common and widespread from c.1300.
Occurrences in the Gersum Corpus
MS <roþu> with a nasal suspension stroke above the <u> is usually expanded to roþun (see Vant). Morris glossed 'rush'.