What does polysīgma mean in Latin?

polysīgma, a noun, means “overuse of the sound "s" in speaking”.

What is the genitive of polysīgma?

The genitive singular is polysīgmatis. polysīgma is neuter, third declension.

In classical Latin, [pɔ.lyˈsiːɡ.ma]; in ecclesiastical (church) Latin, [po.liˈs̬iɡ.ma].

noun · neuterthird declension

polysīgma n sg (genitive polysīgmatis)

Classical[pɔ.lyˈsiːɡ.ma]Ecclesiastical[po.liˈs̬iɡ.ma]

pŏlўsigma πολύ-σίγμα,

I. a too frequent repetition of the letter s: ubi s littera crebrius geminatur: Sosia in Solario soleas sarciebat suas, Mart. Cap. 5, § 514.

Borrowed from Ancient Greek πολῠ́ς (polŭ́s, “many”) + σῖγμᾰ (sîgmă, “sigma”).