'half-sister'(Modern English half-sister)
In the orthography of the Gaw MS <u> sometimes stands for /y/ < late OE /y/ (see GDS p. xlvii, TGD pp. 133–4), and in that case could contain /y/ as in ON, cp. OIcel systir, in which case the form could derive directly from ON (thus GDS). Scandinavian input is likely in this form in light of the difficulty in obtaining late OE /y/ in this word other than < ON /y/, cp. OIcel systir ‘sister’, Runic Norw swestor < PGmc *swestēr, *swestōr; cp. OE sweostor (swester, swustor etc.), Go swistar, OFris swester, OS swestar, OHG swester. Loss of /w/ is not especially distinctive, and can be paralleled in e.g. OFris suster, MDu and MLG suster (see further Boutkan/Siebinga s.v. swester). The source of ON /y/ is generally accounted for as */we/ > */wi/ by i-mutation in the nom./acc. pl. *swistriR; this vowel was then generalized throughout the paradigm, and developed further (perhaps via a diphthongal stage */ui/) > /y/, probably as the result of labial mutation in the acc./gen./dat. sg. form (*suistur > systur) (see Heusler §75.1, Noreen §77.12, Brøndum-Nielsen §88, de Vries, Bj-L). Alternatively the <u> spelling in the Gaw MS could stand for /u/, and <suster> would then be more likely to represent a native development from OE swustor (on swu- > su- here see e.g. OED s.v. sister n., Jordan-Crook §36 Rem. 2). See also sister-sunes.
Proposed ON Etymon (OIcel representative)
(ONP systir (sb.))
Other Scandinavian Reflexes
Far systir, Icel systir, runic Norw swestar, Norw syster, ODan runic systiʀ, ODan systir, systær, Dan søster, Sw syster
sweostor (swester, swustor etc.) 'sister'
Phonological and morphological markers
[/y/ < ON /y/] (may not be applicable)
ME forms in <i, y> are found as early as a1325(c1250) Gen.& Ex.(Corp-C 444). They are widespread across the N, EM and EAngl, but scarcely found at all in the SWM or S (Electronic LALME (map 2430001). LAEME dot map 01949601 plots only a handful of occurrences, in Yks. and Nrf. Spellings in <u> are commonplace in MED (though LALME dot map 518 indicates that, other than in the NW, esp. Chesh. and Lan., spellings of this type were rare in the N/EM (or much in the SW) by later ME).
Occurrences in the Gersum Corpus