ˈzīˌlēn noun
( -s )
Etymology: International Scientific Vocabulary xyl- + -ene
1. : any of three toxic flammable oily isomeric aromatic hydrocarbons C 6 H 4 (CH 3 ) 2 that are dimethyl homologues of benzene and are obtained from wood tar or commercially in mixtures of the three with ethylbenzene from light oils from coal tar or coke-oven gas or from petroleum distillates by processes for producing toluene:
a. : the ortho isomer used chiefly in making phthalic anhydride — called also ortho-xylene, o-xylene
b. : the para isomer used chiefly in making terephthalic acid — called also para-xylene, p-xylene
c. : the meta isomer occurring in the mixtures in larger amounts than the other components and used chiefly in making isophthalic acid and xylidines — called also meta-xylene, m-xylene
2. : a commercial mixture containing xylenes and ethylbenzene used chiefly as a solvent, as a blending agent especially in aviation gasoline, or in making xylidines