WordNet sense 1 (lying with head on paws as if sleeping):

sleeping

WordNet sense 2 (not upright in position or posture):

unerect

WordNet sense 3 (in a condition of biological rest or suspended animation):

torpid, hibernating

WordNet sense 4 (being quiet or still or inactive):

quiescent

WordNet sense 5 (not active physically or mentally):

inactive