ძამა, from ძამან. Compare Svan ჯგმილ, Mingrelian ჯიმა, Laz ჯუმა. According to Georgian linguists, at first it was ძამან, then ნ was omitted from the word. Because of the Svan and Mingrelian forms, linguists believed that this word also had a stem vowel, which should be ა since the Laz-Mingrelian vowel უ corresponds to Georgian ა. Also, see ძამ-ა and ძამ-იკო where the vowel has not dropped out. So the stem was ძამ. Also, ჯიმა and ჯუმა (Mingrelian-Laz forms) have as their plural forms ჯიმ-ალ-ეფ and ჯუმ-ალ-ეფ, but the Mingrelian-Laz suffix for pluralization is -ეფ. So in the plural forms of ჯიმა and ჯუმა, the consonant ლ is restored, which originally must had been in the singular.
- Shota Dzidziguri, The life of the word, 1988.