Dictionary Definition:
upasad 1
upa-√sad P. -sīdati (Ved. Pot. 1. pl. -sadema
• impf. -asadat) to sit upon (acc.) RV. vi, 75, 8
• to sit near to, approach (esp. respectfully), revere, worship RV. AV. TS. ŚBr. &c. MBh. Ragh. &c
• to approach (a teacher in order to become his pupil) Kathās. [Page 209, Column 2]
• to approach asking, request, crave for RV. i, 89, 2 ; vii, 33, 9 TS. ii ŚBr. ii
• to approach in a hostile manner BhP. vi, 3, 27
• to possess RV. viii, 47, 16 AV. iii, 14, 6
• to perform the Upasad ceremony ( below) TS. vi, 2, 3, 4: Caus. -sādayati, to place or put upon or by the side of TS. TBr. ŚBr. &c
• to cause to approach, lead near ( upa-sādita)
upasad 2
upa-sád mfn. approaching (respectfully), worshipping, serving AV. VS. xxx, 9
• (t), m. N. of a particular fire (different from the Gārhapatya, Dakshiṇāgni, and Āhavanīya) VahniP
• (t), f. attendance, worship, service RV. ii, 6, 1
• settlement (?) AV. vi, 142, 3
• siege, assault ŚBr. iii AitBr. Kāṭh
• N. of a ceremony or sacrificial festival preceding the Sutyā or pressing of the Soma (it lasts several days, and forms part of the Jyotishṭoma) VS. xix, 14 TS. ŚBr. KātyŚr. &c