During sleep, most systems in an animal are in an anabolic state, building up the immune, nervous, skeletal, and muscular systems. Sleep in non-human animals is observed in mammals, birds, reptiles, amphibians, and fish, and, in some form, in insects and even in simpler animals such as nematodes. The internal circadian clock promotes sleep daily at night in diurnal species (such as humans) and in the day in nocturnal organisms (such as rodents).
tyrannical - characteristic of an absolute ruler or absolute rule; having absolute sovereignty; an authoritarian regime; autocratic government; despotic rulers; a dictatorial rule that lasted for the duration of the war; a tyrannical government. authoritarian, tyrannic, autocratic, despotic, dictatorial.
Freebase(0.00 / 0 votes)Rate this definition: Tyrant. A tyrant, in its modern English usage, is a ruler of a cruel and oppressive character who is an absolute ruler unrestrained by law or constitution, and/or one who has usurped legitimate sovereignty.