(4) paret w.m. 92, parwyt b.t. 27 (the latter obsolete), pl. parwydydd ‘walls’ (of a house).
(5) gwarthafl ‘stirrup’, Mn. W. gwarthol (‑afl > ‑awl > ‑ol), pl. gwarthafleu, Mn. gwarthaflau.
(6) dydd ‘day’, dyw in dyw Sul etc., pl. dyddiau, dī́au.
ii. A noun may have a sg. form with, and one without, a sg. ending; as deigr, deigryn ‘tear’, pl. dagrau; erfyn, arf ‘weapon’, pl. arfau § 129 i (1); edau, edefyn ‘thread’, pl. edafedd, § 125 iii. The diminutive form has sometimes a pl. of its own; as dafn ‘drop’, pl. dafnau § 122 ii (2), and defnyn ‘drop’, pl. defnynnau § 126 iii; cainc ‘branch’, pl. cangau, ceinciau § 129 i (3); cangen ‘branch’, pl. canghennau T.A. g. 251.
iii. Nouns ending in ‑yn or ‑en, Class 1 § 126 i, may have two singulars, (1) one formed with each ending; thus adar ‘birds’, sg. m. aderyn and f. adaren b.b. 107, the latter obsolete; ysgall ‘thistles’, sg. ysgellyn and ysgallen, both in use; cawn, sg. conyn ‘stalk’, cawnen ‘rush’; gwḯal or gwḯail, sg. gwïalen, or gwïelyn c.c. 265.
(2) With different vowel changes; as dail ‘leaves’, old sg. dalen § 126 i (2), newer sg. deilen, re-formed from the pl. § 126 i (1).
Desynonymized Doublets.
§ 131. i. Many pl. doublets, especially those with different endings, § 129 i (2), have been desynonymized, some early, as bronneu w.m. 94, D.G. 233 ‘breasts’, bronnyẟ m.a. i 415, D.G. 70, ‘hills’, sg. bron ‘breast, hill’; personiaid § 123 iv (1) ‘parsons’, personau ‘persons’ (personẏeu c.m. 19), sg. person in both senses. The following occur in Mn. W.: canoniaid ‘canons’ (men), canonau ‘regulations’, sg. canon; cynghorion ‘counsels’, cynghorau ‘councils’, sg. cyngor; llwythau ‘tribes’, llwythi ‘loads’ (but llwythau ‘loads’ Ex. v 5, vi 6, llwythi ‘tribes’ J.D.R. 291), sg. llwyth; prydiau ‘times’, prydau ‘meals’, sg. pryd; pwysau ‘weights’, pwysi ‘lbs.’, sg. pwys; ysbrydion ‘spirits’ (beings), ysbrydoedd ‘spirits’ in other senses (but Ml. W. ysprydoeẟ, s.g. 308–9, ysprydẏeu do. 310, both in the former sense); anrheithiau ‘spoils’, anrheithi ‘dear ones’, sg. anrhaith ‘booty; darling’, § 156 ii (1).
