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Webster 1913 Edition

Noun.

[L.

but

yrum butter +

-yl

. See

(Chem.)

A compound radical, regarded as butane, less one atom of hydrogen.

butyl ‎(plural butyls)

(organic chemistry) Either of four isomeric univalent hydrocarbon radicals, C₄H₉, formally derived from butane by the loss of a hydrogen atom.
A synthetic rubber made by the polymerization of isobutylene.

either of four isomeric univalent hydrocarbon radicals, C₄H₉

synthetic rubber made by the polymerization of isobutylene

Hyphenation: bu‧tyl

From but- +‎ -yl.

butyl n ‎(uncountable)