a heavy odorless colorless gas formed during respiration and by the decomposition of organic substances; absorbed from the air by plants in photosynthesis
conforming with or constituting a norm or standard or level or type or social norm; not abnormal; "serve wine at normal room temperature"; "normal diplomatic relations"; "normal working hours"; "normal word order"; "normal curiosity"; "the normal course of events"
being approximately average or within certain limits in e.g. intelligence and development; "a perfectly normal child"; "of normal intelligence"; "the most normal person I've ever met"
not original; not being or productive of something fresh and unusual; "the manuscript contained unoriginal emendations"; "his life had been unoriginal, conforming completely to the given pattern"- Gwethalyn Graham
the act of drilling a hole in the earth in the hope of producing petroleum
so lacking in interest as to cause mental weariness; "a boring evening with uninteresting people"; "the deadening effect of some routine tasks"; "a dull play"; "his competent but dull performance"; "a ho-hum speaker who couldn't capture their attention"; "what an irksome task the writing of long letters is"- Edmund Burke; "tedious days on the train"; "the tiresome chirping of a cricket"- Mark Twain; "other people's dreams are dreadfully wearisome"
air passage provided by a retractable device containing intake and exhaust pipes; permits a submarine to stay submerged for extended periods of time
breathing device consisting of a bent tube fitting into a swimmer's mouth and extending above the surface; allows swimmer to breathe while face down in the water