Definition of be parallel:
(adj) :
of two or more (straight) lines, (flat) surfaces etc:
Equally distant from one another at all points; parallel to: Of one thing, relative to another: Equally distant from at all points
"the horizontal lines on my notebook paper are parallel."
"the 31st parallel passes through the center of my town."
(v) :
to
construct something parallel to something else; of a path etc: To be parallel to something else