Webster's English Dictionary

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respiration

res.pi.ra.tion \.res-p*-'ra--sh*n\ \-shn*l, -sh*n-*l\ 
   \'res-p(*-)r*-.to-r-e-, ri-'spi--r*-, 'res-p*-.to-r-, -.to.r-\ n 1a: the 
   placing of air or dissolved gases in intimate contact with the circ ulating 
   medium of a multicellular organism (as by breathing) 1b: a single complete 
   act of breathing  2: the physical and chemical processes by which an 
   organism supplies its ce lls and tissues with the oxygen needed for 
   metabolism and relieves them of the carbon dioxide formed in 
   energy-producing reactions 3: any of various energy-yielding oxidative 
   reactions in living matter  - res.pi.ra.tion.al aj