Fence
Middle English (in the sense ‘defending, defence’): shortening of defence. Compare with fencible and fend.
wiktionary
From Middle English fence, fens, short for defence, defens(“the act of defending”), from Old French defens, defense (see defence).
The sense "enclosure" arises in the mid 15th century. Also from the 15th century is use as a verb in the sense "to enclose with a fence". The generalized sense "to defend, screen, protect" arises ca. 1500. The sense "to fight with swords (rapiers)" is from the 1590s (Shakespeare).
Displaced native Old English edor.
etymonline
fence (n.)
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].
fence (v.)
early 15c., "defend" (oneself); mid-15c. as "protect with a hedge or fence;" from fence (n.). From 1590s as "fight with swords," from the noun in this sense (1530s); see fencing. From 1610s as "knowingly buy or sell stolen goods." Related: Fenced.
