n.
Gaw, Pe forþe
'ford'
(Modern English ford)ME ford- with root-final stop (as in Gaw 699 <fordez>) clearly derives from OE ford (occasionally wk. forda) ‘ford’; cp. OS -ford (only in place-names), OHG furt and the OFris n-stem forda, supposing a PGmc root *furð-. No such form is attested in Go or the Scandinavian languages, but it is generally agreed that an Ablaut variant *ferþ- lies behind ON fjǫrðr ‘firth, fjord, inlet’ < PGmc *ferþuz. MED is unique in suggesting that ME variants in -th or -þ ‘may owe the final consonant to Norse influence’ and the absence of a direct ON cognate makes it implausible. Similarly, either a sound-substitution of /ð/ for /d/ based on other ON-OE cognate pairs, or some cross-influence from ON fjǫrðr (though there is no evidence that the latter was ever borrowed into medieval English, and it is not found in English place-names) is possible, but entirely speculative. Most explain ME forth as the result of various native processes, e.g. the late ME and early ModE development of -rd- to -rth- in unstressed syllables (EPNE) or spirantization processes by which the /ð/ ~ /d/ distinction was regularly neutralized in the neighbourhood of liquids (McL 110-11). There might also be some association with the OE adv. forþ (as a ford is a way forward, through a water-course).
PGmc Ancestor
*furð-
Proposed ON Etymon (OIcel representative)
cp. fjǫrðr ‘firth, fjord, inlet’
(ONP )
Other Scandinavian Reflexes
OE Cognate
ford 'ford'
Phonological and morphological markers
[ON fricative /ð/ < PGmc */ð/] (possibly diagnostic)
Summary category
CCC2bc
DOE cites the variant <forð> only from two 12c. and 13c. MSS. Variants in -th, -þ are fairly widespread by late ME, but in place-names, forth seems mainly to be N (see EPNE).
Occurrences in the Gersum Corpus
Gaw 1585, 1617; Pe 150