(of quantities) imprecise but fairly close to correct; "lasted approximately an hour"; "in just about a minute"; "he's about 30 years old"; "I've had about all I can stand"; "we meet about once a month"; "some forty people came"; "weighs around a hundred pounds"; "roughly $3,000"; "holds 3 gallons, more or less"; "20 or so people were at the party"
a journey or route all the way around a particular place or area; "they took an extended tour of Europe"; "we took a quick circuit of the park"; "a ten-day coach circuit of the island"
make a tour of a certain place; "We toured the Provence this summer"
(figurative) a course of action that is unproductive and offers no hope of improvement; "all the clues led the police into blind alleys"; "so far every road that we've been down has turned out to be a blind alley"
absolutely required and not to be used up or sacrificed
absolutely necessary; vitally necessary; "essential tools and materials"; "funds essential to the completion of the project"; "an indispensable worker"
being or relating to or containing the essence of a plant etc; "essential oil"