AUTOCRAT
tyrant, autocrat, despot
(noun) a cruel and oppressive dictator
Source: WordNet® 3.1
Etymology
Noun
autocrat (plural autocrats)
An absolute ruler with infinite power.
Synonyms: autocrator, despot, dictator, monarch, tyrant, strongman
A title borne by some such monarchs, as in Byzantium and tsarist Russia.
Anagrams
• actuator
Source: Wiktionary
Au"to*crat, n. Etym: [Gr. autocrate. See Hard, a.]
1. An absolute sovereign; a monarch who holds and exercises the
powers of government by claim of absolute right, not subject to
restriction; as, Autocrat of all the Russias (a title of the Czar).
2. One who rules with undisputed sway in any company or relation; a
despot.
The autocrat of the breakfast table. Holmes.
Source: Webster’s Unabridged Dictionary 1913 Edition