Old English *willan, wyllan “to wish, desire; be willing; be used to; be about to” (past tense wolde), from Proto-Germanic *willjan (source also of Old Saxon willian, Old Norse vilja, Old Frisian willa, Dutch willen, Old High German wellan, German wollen, Gothic wiljan “to will, wish, desire,” Gothic waljan “to choose”).
The Germanic words are from PIE root *wel- (2) “to wish, will” (source also of Sanskrit vrnoti “chooses, prefers,” varyah “to be chosen, eligible, excellent,” varanam “choosing;” Avestan verenav- “to wish, will, choose;” Greek elpis “hope;” Latin volo, velle “to wish, will, desire;” Old Church Slavonic voljo, voliti “to will,” veljo, veleti “to command;” Lithuanian velyti “to wish, favor,” pa-velmi “I will,” viliuos “I hope;” Welsh gwell “better”).
Compare also Old English wel “well,” literally “according to one’s wish;” wela “well-being, riches.” The use as a future auxiliary was already developing in Old English. The implication of intention or volition distinguishes it from shall, which expresses or implies obligation or necessity. Contracted forms, especially after pronouns, began to appear 16c., as in sheele for “she will.” In early use often -ile to preserve pronunciation. The form with an apostrophe (‘ll) is from 17c.
Old English will, willa “mind, determination, purpose; desire, wish, request; joy, delight,” from Proto-Germanic *wiljon- (source also of Old Saxon willio, Old Norse vili, Old Frisian willa, Dutch wil, Old High German willio, German Wille, Gothic wilja “will“), related to *willan “to wish” (see will (v.1)). The meaning “written document expressing a person’s wishes about disposition of property after death” is first recorded late 14c.
Old English willian “to determine by act of choice,” from will (n.). From mid-15c. as “dispose of by will or testament.” Often difficult to distinguish from will (v.1).
also wilful, c. 1200, “strong-willed,” usually in a bad sense, “obstinate, unreasonable,” from will (n.) + -ful. From late 14c. as “eager” (to do something). Mid-14c., of actions, “done on purpose, intentional, due to one’s own will.” Related: Willfullness.
early 14c., present-participle adjective from will (v.1). Old English had -willendliche in compounds. Related: Willingly; willingness.
Old English godes willan “state of wishing well to another;” see good (adj.) + will (n.). Meaning “cheerful acquiescence” is from c. 1300. In the commercial sense “degree of favor enjoyed through patronage of customers” from 1570s.
1660s, earlier Will with the wisp (c. 1600), from the masc. proper name Will + wisp “bundle of hay or straw used as a torch.” Compare Jack-o’-lantern.
late 14c., from Latin voluntarius “willing, of one’s free will,” from voluntas “will,” from the ancient accusative singular present participle of velle “to wish” (see will (v.)). Originally of feelings, later also of actions (mid-15c.). Related: Voluntarily.
1610s, from French volition (16c.), from Medieval Latin volitionem (nominative volitio) “will, volition,” noun of action from Latin stem (as in volo “I wish”) of velle “to wish,” from PIE root *wel- (2) “to wish, will” (see will (v.)). Related: Volitional.
Old English nylle, nelle “to be unwilling,” from ne “no” (from PIE root *ne- “not”) + will (v.). Often paired with will; the once-common construction nill he, will he, attested from c. 1300, survives principally in willy-nilly, which, however, reverses the usual Middle English word order. Latin expressed a similar idea in nolens volens.
Source: O
etymonline.com
oxford dictionary