section (n.) Look up section at Dictionary.com
late 14c., "intersection of two straight lines; division of a scale;" from Old French section or directly from Latin sectionem (nominative sectio) "a cutting, cutting off, division," noun of action from past participle stem of secare "to cut," from PIE root *sek- "to cut" (cognates: Old Church Slavonic seko, sešti "to cut," se čivo "ax, hatchet;" Lithuanian isekti "to engrave, carve;" Albanian šate "mattock;" Old Saxon segasna, Old English sigðe "scythe;" Old English secg "sword," seax "knife, short sword;" Old Irish doescim "I cut;" Latin saxum "rock, stone").

From 1550s as "act of cutting or dividing." Meaning "subdivision of a written work, statute, etc." is from 1570s. Meaning "a part cut off from the rest" is from early 15c.
section (v.) Look up section at Dictionary.com
"divide into sections," 1819, from section (n.). Related: Sectioned; sectioning.