Inventory
late Middle English: from medieval Latin inventorium, alteration of late Latin inventarium, literally ‘a list of what is found’, from Latin invenire ‘come upon’.
wiktionary
From Middle English inventorie, from Old French inventoire (whence French inventaire), from Late Latin inventarium, from Latin invenire(“to find out”).
etymonline
inventory (n.)
early 15c., from Old French inventoire "detailed list of goods, a catalogue" (15c., Modern French inventaire), from Medieval Latin inventorium, alteration of Late Latin inventarium "list of what is found," from Latin inventus, past participle of invenire "to find, discover, ascertain" (see invention).
The form was altered in Medieval Latin by influence of words in -orium, which became very common in post-classical and Christian use. It properly belongs with words in -ary, and French has corrected the spelling. Related: Inventorial; inventorially.
inventory (v.)
"make a list or catalogue of," c. 1600, from inventory (n.). Related: Inventoried; inventorying.