intersect (n.)

"point of intersection," 1850, from intersect (v.) or from Latin intersectum, neuter past pasticiple of intersecare. Earlier (1650s) it was used for "an insect."

intersect (v.)

1610s (trans.), back-formation from intersection, or else from Latin intersectus, past participle of intersecare "intersect, cut asunder," from inter "between" (see inter-) + secare "to cut" (from PIE root *sek- "to cut"). Intransitive sense is from 1847. Related: Intersected; intersecting.