In this article in the jewishencyclopedia it mentions some tomb galleries:
These galleries, or niches, which were called "kok" (plural, "kokim") by the Rabbis.
I want to know how those two words (kok, kokim) are written in Hebrew.
I know the word קֶבֶר (keber), but not those ones.
Here's the Jastrow entry:
כּוּךְ m. (= כוכו, v. כַּוָּוא) cavity, cave, esp. sepulchral chamber. [Taan. 25ᵇ כ׳ המחרישה R. Gersh. (Ms. M. כון, v. Rabb. D. S. a. l. note, ed. בֶּרֶךְ) the cavity made by the plough.]—Y. B. Bath. III, beg. 13ᵈ חמוכר … בכ׳ חזקה לכל הכ׳ if one sells a burial place (קבר) to his neighbor, as soon as the latter has buried one dead in the chamber, he has the possession of the entire chamber; a. e.—Pl. כּוּכִין. Ib. קבר … בג׳ כ׳ וכ׳ when he buried three dead in three different chambers &c. Tosef. Ohol. XVII, 11 [read:] … שדה … בתוכה היא כשדה כ׳ ואיזו היא שדה כ׳ כל חכ׳ לצדדין a field in which a grave (known to have been there) has disappeared, is like a field of sepulchral chambers. And what is a field &c.? Where you dig out (a square) in the ground, and make chambers in the walls. B. Bath. VI, 8; a. e.
כּוּךְ, כּוֹכָא ch. 1) same. Targ. Job XXX, 2; ib. V, 26 (h. text כלח).). —2) an improvised subterranean dwelling. Taan. 22ᵃ ככ׳ דציידי Rashi (ed. ככוּכֵי, pl., Ar. s. v. ככי: לא נצרכה אלא לבי כ׳ דאגמא) like the hunters’ cave. Gitt. 68ᵃ bot. מטא גבי כ׳ דההיא וכ׳ Ar. (ed. כובא, corr. acc.) he came to the hut of a certain widow. [Ber. 37ᵇ כ׳ דארעא Ar., v. כּוּבָּא III.]
