Despotic, Despotical, a.
Etymology: [Gr. despotique.]
Having the character of, or pertaining to, a despot; absolute in power; possessing and abusing unlimited power; evincing despotism; tyrannical; arbitrary. -- Des*pot"ic*al*ly, adv. -- Des*pot"ic*al*ness, n.
Shades of meaning
Fernald has no entry of its own for despotic; he lists it under absolute.
Where he writes about it:
Despotic is commonly applied to a masterful or severe use of power, which is expressed more decidedly by tyrannical. — from absolute