to subside, sink; to yield, give way SN.i.53; Snp.939 (= saṃsīdati osīdati Cnd.420); Iti.71; Mhvs.35, Mhvs.35 3^rd pl. sīdare Ja.ii.393; Pot. sīde Iti.71; fut. sīdissati: see ni˚
pp sanna
caus sādeti (q.v.); Caus. II sīdāpeti to cause to sink Sdhp.43
■ Cp. ni˚, vi˚.

sad, Idg. *si-ƶd-ō, redupl. formation like tiṣṭhati; cp. Lat. sīdo, Gr. ι ̔́ζω; Av. hidaiti
■ The Dhtp (50 gives the 3 meanings of “visaraṇa-gaty-avasādanesu”.