Any saturated aliphatic monohydric alcohol of the formula C₈ H₁₇ OH, of which many isomeric forms exist; especially (a) (also "n-octanol" or "1-octanol") the primary straight-chain isomer, CH₃ (CH₂)₆ CH₂ OH, or (b) (also "2-octanol") the secondary straight-chain isomer, CH₃ (CH₂)₅ CH(OH)CH₃, both of which are colourless odoriferous liquids used chiefly in the perfume and plastic industries.