Dictionary Definition:
upa-śama m. the becoming quiet, assuagement, alleviation, stopping, cessation, relaxation, intermission MāṇḍUp. Prab. Pañcat. &c
• tranquillity of mind, calmness, patience MBh. iii Bhartṛ. Śāntiś
• (in astron.) N. of the twentieth Muhūrta