ˈzīlə̇l noun
( -s )
Etymology: International Scientific Vocabulary xyl- + -yl
: any of several isomeric univalent radicals C 8 H 9 derived from the three xylenes by removal of a hydrogen atom ; especially : a radical of the formula (CH 3 ) 2 C 6 H 3 −; dimethyl-phenyl — compare tolyl