Item
late Middle English (as an adverb): from Latin, ‘in like manner, also’. The noun sense arose (late 16th century) from the use of the adverb to introduce each statement in a list.
wiktionary
From Middle English item, from Latin item(“also; in the same manner”). The present English meaning derives from a usage in lists, where the first entry would begin in primis (“firstly”) or imprimis, and the other entries with item(“also, moreover”). Later, the members of lists were referred to as "items".
etymonline
item (n.)
late 14c., originally an adverb, "moreover, in addition," from Latin item (adv.) "likewise, just so, moreover," probably from ita "thus," id "it" (see id) + adverbial ending -tem (compare idem "the same").
The Latin adverb was used to introduce a new fact or statement, and in French and English it was used before every article in an enumeration (such as an inventory or bill). This practice led to the noun sense "an article of any kind" (1570s). Meaning "detail of information" (especially in a newspaper) is from 1819; item "sexually linked unmarried couple" is 1970, probably from notion of being an item in the gossip columns.
