Defn: Eightfold.

OCTYL
Oc"tyl, n. Etym: [Octane + -yl.] (Chem.)

Defn: A hypothetical hydrocarbon radical regarded as an essential residue of octane, and as entering into its derivatives; as, octyl alcohol.

OCTYLENE
Oc"tyl*ene, n. Etym: [Octane + ethylene.] (Chem.)

Defn: Any one of a series of metameric hydrocarbons (C8H16) of the ethylene series. In general they are combustible, colorless liquids.

OCTYLIC
Oc*tyl"ic, a. (Chem.)

Defn: Pertaining to, derived from, or containing, octyl; as, octylic ether.

OCULAR Oc"u*lar, a. Etym: [L. ocularis, ocularius, fr. oculus the eye: cf.F. oculaire. See Eye, and cf. Antler, Inveigle.]

1. Depending on, or perceived by, the eye; received by actual sight; personally seeing or having seen; as, ocular proof. Shak. Thomas was an ocular witness of Christ's death. South.

2. (Anat.)