Find the word definition

Wiktionary
heptadecane

n. (context organic compound English) An alkane hydrocarbon with the chemical formula CH3(CH2)15CH3.

Wikipedia
Heptadecane

Heptadecane is an organic compound, an alkane hydrocarbon with the chemical formula CH. The name may refer to any of 24894 theoretically possible structural isomers, or to a mixture thereof.

The unbranched isomer is normal or n-heptadecane, CH(CH)CH. In the IUPAC nomenclature, the name of this compound is simply heptadecane, since the other isomers are viewed and named as alkyl-substituted versions of smaller alkanes.

The most compact and branched isomer would be 3,3-di-tert-butyl-2,2,4,4-tetramethylpentane, but its existence is believed to be impossible due to steric hindrance. Indeed, it is believed to be the smallest "impossible" alkane.