In the “Etymological Dictionary of Slavic Languages”, O. N. Trubachev explained Proto-Slavic dial. *meldĭnŭ (with reflexes attested in the Western part of the South Slavic area; cf. Serbo-Croatian mledan, Slovene mleden ‘weak, feeble; soft, sensitive’, etc.) as a derivative of the root *meld-, related to Proto-Slavic *moldŭ ‘soft; young’ (cf. Old Church Slavonic mladŭ ‘young’, Russian molodói ‘id.’, etc.; ultimately from Indo-Euro-pean *meld- ‘to grind, hit; fine’). This interpretation may be further elaborated by assuming that Proto-Slavic *meldĭnŭ is derived from Proto-Slavic dial. *meldŭ ‘soft’ which is a parallel formation (with root ablaut) to Proto-Slavic *moldŭ; cf. Old Irish mell ‘pleasant, delightful’, possibly from Proto-Celtic *meldo- ‘mild, pleasant’ corresponding to Proto-Slavic *meldŭ (*o-stem formation). Cf. also Russian dial. meledit' ‘be slow/tardy, delay, linger, etc.’ as a possible reflex of Proto-Slavic *melditi (denominative verb of *meldŭ). — In addition to *meld-ĭnŭ, Proto-Slavic *meldŭ also seems to have been enlarged, by means of other Proto-Slavic suffixes, to *meld-jĭ (cf. Slovak dial. mliedzi ‘weak, puny, sickly; [of a meal] not substantial’) and *meld-rŭ (reconstructed from Slovak mľandravý ‘soft, flabby, languid’ < mlendravý < *mledr-avý). — At the same time, the Russian and Slovak data allow the conclusion that, in addition to the Slavic South, Proto-Slavic dial. *meldŭ also existed in East and West Slavic area.