"low-quality," , "shared by all," from imene , from Old English gemæne "common, public, general, universal, shared by all," from Proto-Germanic *ga-mainiz "possessed jointly" (cf. Old Frisian mene , Old Saxon gimeni , Middle Low German gemeine , Middle Dutch gemene , Dutch gemeen , German gemein , Gothic gamains "common"), from PIE *ko-moin-i- "held in common," a compound adjective formed from collective prefix *ko- "together" (Proto-Germanic *ga- ) + *moi-n- , suffixed form of PIE root *mei- "to change, exchange" (see mutable ). Cf. second element in common (adj.), a word with a sense evolution parallel to that of this word.
Of things, "inferior, second-rate," from late 14c. (a secondary sense in Old English was "false, wicked"). Notion of "so-so, mediocre" led to confusion with mean (n.). Meaning "inferior in rank or status" (of persons) emerged early 14c.; that of "ordinary" from late 14c.; that of "stingy, nasty" first recorded 1660s; weaker sense of "disobliging, pettily offensive" is from 1839, originally American English slang. Inverted sense of "remarkably good" (. plays a mean saxophone ) first recorded , perhaps from phrase no mean _______ "not inferior" (1590s, also, "not average," reflecting further confusion with mean (n.)).
Recuse is derived from the Anglo-French word recuser, which comes from Latin recusare, meaning "to refuse." English speakers began using "recuse" with the meaning "to refuse or reject" in the 14th century. By the 17th century, the term had acquired the meaning "to challenge or object to (a judge)." The current legal use of "recuse" as a term specifically meaning "to disqualify (oneself) as a judge" didn't come into frequent use until the mid-20th century. Broader applications soon followed from this sense - you can now recuse yourself from such things as debates and decisions as well as court cases.
There are a lot of other subtleties to gas, but that should give you the basics! Gas is the key mechanism that makes the complex computations in Ethereum "safe" for the network to work on , because any programs that run out of control will only last as long as the money provided by the people who requested they be run. When the money stops, the miners stop working on it. And the mistakes you make in your program will only affect the people who pay to use it --the rest of the network can't suffer performance issues due to your error. They will simply get a big payday when the performance issues consume all of your ether! Without this critical technique, the idea of a general-purpose blockchain would have been completely impossible.