Any saturated aliphatic monohydric alcohol of the formula C₈H₁₇OH, of which many isomeric forms exist; especially (a) (also "n-octanol" or "1-octanol") the primary straight-chain isomer, CH₃(CH₂)₆CH₂OH, or (b) (also "2-octanol") the secondary straight-chain isomer, CH₃(CH₂)₅CH(OH)CH₃, both of which are colourless odoriferous liquids used chiefly in the perfume and plastic industries.