Is it ensure, insure, or assure?
Old English stæf "walking stick, strong pole used for carrying, rod used as a weapon" (also, in plural, "letter, character, writing," cf. stæfcræft "grammar"), from Proto-Germanic *stabaz (cf. Old Saxon staf, Old Norse stafr, Old Frisian stef, Middle Low German and Middle Dutch staf, Old High German stab, German Stab, Gothic *stafs "element;" Middle Dutch stapel "pillar, foundation"), from PIE root *stebh- "post, stem, to support, place firmly on, fasten" (cf. Old Lithuanian stabas "idol," Lithuanian stebas "staff, pillar;" Old Church Slavonic stoboru "pillar;" Sanskrit stabhnati "supports;" Greek stephein "to tie around, encircle, wreathe," staphyle "grapevine, bunch of grapes;" Old English stapol "post, pillar").
Sense of "group of military officers that assists a commander" is attested from 1702, apparently from German, from the notion of the "baton" that is a badge of office or authority (a sense attested in English from 1530s). Meaning "group of employees (as at an office or hospital)" is first found 1837. Staff of life "bread" is from the Biblical phrase "to break the staff of bread" (Lev. xxvi:26), translating Hebrew matteh lekhem.
"to provide with a staff of assistants," 1859, from staff (n.). Related: Staffed; staffing.
"piece of a barrel," 1750, back-formation from staves (late 14c.), plural of staff (cf. leaves/leaf), possibly from Old English, but not recorded there. The verb (to stave in, past tense stove) is 1590s, originally nautical, on notion of bashing in the staves of a cask and letting out the contents; stave off (1620s) is literally "keep off with a staff," as of dogs.
A specific group of workers.
To provide with a staff of workers or assistants.
To serve on the staff of.
A multiple-car wreck (1950s+ Teenagers)verb phrase
[first two verb-phrase senses fr the stacking up of one's poker chips to show winnings or for comparison]
in the notation of Western music, five parallel horizontal lines that, with a clef, indicate the pitch of musical notes. The invention of the staff is traditionally ascribed to Guido d'Arezzo in about the year 1000, although there are earlier manuscripts in which neumes (signs from which musical notes evolved) are arranged around one or two lines in order to orient the singer. Guido used three or four lines of different colours. A four-line staff is still used to notate plainchant.