< *mrəq‑, W. braenu ‘to rot’ < *mrəq‑n‑, √merāˣq- ‘decay’: Lat. fracēs ‘oil-dregs’, Gk. ἀμόργη (< *ἀμόρκᾱ, whence Lat. amurca Walde² 464).—Similarly Ar. m- before l̥ or r̥, short or long: W. blith ‘milk, milch’, Ir. mlicht, blicht < *ml̥k̑t‑, § 61 i; W. blawd ‘flour’ < *ml̥̄t- § 61 ii.—The same change probably took place medially also; in that position both m and b would now appear as f, but in O. W. ṽ from m is written m, while v from b appears as b; and such a form as amcibret ox. < *m̥bi-kom-(p)ro-ret- § 156 i (9) implies v < b; so Brit. Sabrina probably contains *sam‑. In the Coligny calendar tio-cobrextio very probably contains *kom-rekt- = W. cyfraith, Rhys CG. 16. But. W. cyṽ- < *kom- persisted by analogy: cymreith (m ≡ v) l.l. 120; cf. § 16 iv (3). (Lat. m…l became mb…l in cumulus, stimulus § 66 ii (1).)
(2) Ar. medial ‑lm‑, ‑rm- remained in Pr. Kelt., and ‑lmp‑, ‑rmp- became ‑lm‑, ‑rm‑; they appear so in Ir.; in W. the m appears as f or w̯. Thus W. celfydd ‘skilful’, celfyddyd ‘craft’, O. Bret. celmed gl. efficax, Ir. calma ‘doughty’ < *qₑl’mp‑: Lat. scalpo, Lith. sklempiù ‘I polish’, Skr. kalpanā ‘fashioning, invention’, kl̥ptáḥ ‘arranged, trimmed, cut’: E. skill, Goth. skilja ‘butcher’; √(s)qel‑, extd. *(s)qelep‑;—W. cwrf, cwrw̯, Ml. W. kwrɏf, coll. cwrw for cwrwf or cwrw ‘beer’, Ir. cuirm, Gaul. κοῦρμι, < *korm‑: Lat. cremor ‘thick juice obtained from vegetables’; lit. ‘*decoction’, √qerem- § 95 iii (1);—W. serfyll ‘prostrate’ < *stₑrm‑: Lat. strāmen, Gk. στρῶμα, Skr. stárīman- ‘strewing’, √sterō- § 63 vii (2).—So in old compounds: W. gorfynt ‘envy’, Bret. gourvent, Ir. format < *u̯er-ment‑: Lat. gen. mentis, E. mind: Gk. ὑπερ-μεν-ής with same pref. and root: √men‑; but later compounds may have rm, as gor-moẟ ‘too much’.
Probably the m was already somewhat loose in Brit., as Gaul. ceruesia ‘beer’ beside κοῦρμι shows it to have been in Gaul. Hence new formations with a new m might be treated differently. Thus, in Lat. loanwords, while we have usually lf, rf, as in palf < palma, terfyn < terminus, we may have lm, rm, as in Garmon < Germānus, salm < psalmus, prob. borrowed later.
iii. (1) Ar. ‑nl‑, ‑nr- became ‑ll‑, ‑rr- respectively in Pr. Kelt. Thus W. gwall ‘want, defect’, gwallus Ỻ.A. 154 ‘negligent’, now ‘faulty’, Bret. gwall ‘defect’ < *u̯an-lo‑, √u̯ā̆n‑: Lat. vānus,
