aristocracyyoudaoicibaDictYouDict
aristocracy: [16] Greek áristos meant ‘best’; hence aristocracy signifies, etymologically, ‘rule by the best’ (the suffix -cracy derives ultimately from Greek krátos ‘strength, power’, a relative of English hard). The term aristokratíā was used by Aristotle and Plato in their political writings, denoting ‘government of a state by those best fitted for the task’, and English writers perpetuated the usage when the word was borrowed from French aristocratie: Thomas Hobbes, for instance, wrote ‘Aristocracy is that, wherein the highest magistrate is chosen out of those that have had the best education’, Art of Rhetoric 1679.

But from the first the term was also used in English for ‘rule by a privileged class’, and by the mid 17th century this had begun to pass into ‘the privileged class’ itself, ‘the nobility’. The derived aristocrat appeared at the end of the 18th century; it was a direct borrowing of French aristocrate, a coinage inspired by the French Revolution.
=> hard
focusyoudaoicibaDictYouDict
focus: [17] Latin focus meant ‘fireplace’, and in post-classical times it came to be used for ‘fire’ itself – hence French feu, Italian fuoco, Spanish fuego, all meaning ‘fire’, and hence too the English derivatives fuel and fusillade. The first writer known to have used it in its modern sense ‘point of convergence’ was the German astronomer Johannes Kepler, in 1604, but the reason for his choice of word is not clear.

It may have been some metaphorical notion of the ‘hearth’ symbolizing the ‘centre of the home’, but it has also been suggested that it may have been preceded and inspired by the use of focus for the ‘burning point’ of a mirror (not actually recorded until somewhat later). The philosopher Thomas Hobbes appears to have introduced the term into English, in 1656. A medieval Latin derivative of focus was focārius, from which French got foyer ‘hearth, home’, borrowed by English in the 19th century for a public entrance hall or lobby.
=> foyer, fuel, fusillade