an oppressive quality that is laborious and solemn and lacks grace or fluency; "a book so serious that it sometimes subsided into ponderousness"; "his lectures tend to heaviness and repetition"
(physiology) metabolic equilibrium actively maintained by several complex biological mechanisms that operate via the autonomic nervous system to offset disrupting changes
highly significant or important especially bringing about or marking the beginning of a new development or era; "epochal decisions made by Roosevelt and Churchill"; "an epoch-making discovery"