mid-13c., defenden, "to shield from attack, guard against assault or injury," from Old French defendre (12c.) "defend, resist," and directly from Latin defendere "ward off, protect, guard, allege in defense," from de "from, away" (see de-) + -fendere "to strike, hit, push," attested only in compounds (such as offendere "to strike against; encounter;" infensus "aggressive, hostile"), from PIE root *gwhend- "to strike, kill" (source also of Hittite kue(n)zi "to kill," Sanskrit ghnanti "to kill; Greek theino "to slay, to kill;" Armenian jnem "to strike;" Lithuanian ginti "to protect, defend;" Old Irish gonaid "wounds, kills;" Welsh gwan "to thrust, hit;" Old Breton goanaff "to punish, sting").

It is attested from c. 1300 as "fight in defense of" (someone or something). From mid-14c. as "defend with words, speak in support of, vindicate, uphold, maintain." In Middle English it also could mean "forbid, prohibit; restrain, prevent." In the Mercian hymns, Latin defendet is glossed by Old English gescildeð. Related: Defended; defending.

"dullard, dolt, ignoramus," 1570s, from earlier Duns disciple, Duns man (1520s) "follower of John Duns Scotus" (c. 1265-1308), Scottish scholar of philosophy and theology supposed to have been born at Duns in Berwick. His followers, the Scotists, had control of the universities until the Reformation. By 1520s, humanist reaction against medieval theology had singled him out as the type of the hairsplitting scholastic. It became a general term of reproach applied to obstinate or sophistical philosophical opponents by 1520s, then by 1570s it was extended to any dull-witted student. Dunce's cap is attested by 1792 (compare foolscap).

early 14c., "action of defending, resistance; means of protection, fortification," shortening of defens (see defense). The same pattern also yielded fend, fender; and obsolete fensive "defensive" (late 16c.). Spelling alternated between -c- and -s- in Middle English. Sense of "enclosure" is first recorded mid-15c. on notion of "that which serves as a defense." Sense of "dealer in stolen goods" is thieves' slang, first attested c. 1700, from notion of such transactions taking place under defense of secrecy.

To be figuratively on the fence "uncommitted" is from 1828, perhaps from the notion of spectators at a fight, or a simple literal image: "A man sitting on the top of a fence, can jump down on either side with equal facility." [Bartlett, "Dictionary of Americanisms," 1848].

"(away) from here," late 13c., hennes, with adverbial genitive -s + Old English heonan "away, hence," from West Germanic *hin- (source also of Old Saxon hinan, Old High German hinnan, German hinnen), from PIE *ki-, variant of root *ko- "this," the stem of the demonstrative pronoun (see here).

The modern spelling (mid-15c.) is phonetic, to retain the breathy -s- (compare twice, once, since). Original "away from this place;" of time, "from this moment onward," late 14c.; meaning "from this (fact or circumstance)" first recorded 1580s. Wycliffe (1382) uses hennys & þennys for "from here and there, on both sides."

late 14c., a contraction of penies, collective plural of penny. Spelling with -ce reflects the voiceless pronunciation (compare dice (n.), deuce, hence). After the introduction of decimal currency in Britain in 1971, it began to be used in singular (one pence).

see defense.

also defenceless, "being without means of repelling assault or injury," 1520s, from defense + -less. Related: Defenselessly; defenselessness.

1650s, "act of defending oneself," first in Hobbes, from self- + defense. In sports sense, first with reference to fencing (1728), then boxing and pugilism (1820s).

[I]n law, the act of forcibly resisting a forcible attack upon one's own person or property, or upon the persons or property of those whom, by law, one has a right to protect and defend. [Century Dictionary]