fence off

fence (fɛns)
—n
1.	a structure that serves to enclose an area such as a garden or field, usually made of posts of timber, concrete, or metal connected by wire, netting, rails, or boards
2.	slang a dealer in stolen property
3.	an obstacle for a horse to jump in steeplechasing or showjumping
4.	machinery a guard or guide, esp in a circular saw or plane
5.	a projection usually fitted to the top surface of a sweptback aircraft wing to prevent movement of the airflow towards the wing tips
6.	mend one's fences
	a.  chiefly (US), (Canadian) to restore a position or reputation that has been damaged, esp in politics
	b.  to re-establish friendly relations (with someone)
7.	on the fence unable or unwilling to commit oneself
8.	informal (Austral), (NZ) over the fence unreasonable, unfair, or unjust
9.	sit on the fence to be unable or unwilling to commit oneself
—vb
10.	(tr) to construct a fence on or around (a piece of land, etc)
11.	(tr; foll by in or off) to close (in) or separate (off) with or as if with a fence: he fenced in the livestock
12.	(intr) to fight using swords or foils
13.	(intr) to evade a question or argument, esp by quibbling over minor points
14.	(intr) to engage in skilful or witty debate, repartee, etc
15.	slang (intr) to receive stolen property
16.	archaic (tr) to ward off or keep out
[C14 fens, shortened from defensdefence]
'fenceless
—adj
'fencelike
—adj

fence

from notion of such transactions taking place under defense of secrecy. To be figuratively on the fence "uncommitted" is from 1828, from the notion of spectators at a fight.

fence

"fight with swords," 1590s, first recorded in "Merry Wives of Windsor"; from the noun in this sense (1530s), see fence (n.). In spite of the re-enactment in 1285 of the Assize of Arms of 1181, fencing was regarded as unlawful in England. The keeping of fencing schools was

forbidden in the City of London, "as fools who delight in mischief do learn to fence with buckler, and thereby are encouraged in their follies."

fence

n.
1. A sequence of one or more distinguished (out-of-band) characters (or other data items), used to delimit a piece of data intended to be treated as a unit (the computer-science literature calls this a `sentinel'). The NUL (ASCII 0000000) character that terminates strings in C is a fence. Hex FF is also (though slightly less frequently) used this way. See zigamorph.
2. An extra data value inserted in an array or other data structure in order to allow some normal test on the array's contents also to function as a termination test. For example, a highly optimized routine for finding a value in an array might artificially place a copy of the value to be searched for after the last slot of the array, thus allowing the main search loop to search for the value without having to check at each pass whether the end of the array had been reached.
3. [among users of optimizing compilers] Any technique, usually exploiting knowledge about the compiler, that blocks certain optimizations. Used when explicit mechanisms are not available or are overkill. Typically a hack: "I call a dummy procedure there to force a flush of the optimizer's register-coloring info" can be expressed by the shorter "That's a fence procedure".

Fence definition

(Heb. gader), Num. 22:24 (R.V.). Fences were constructions of unmortared stones, to protect gardens, vineyards, sheepfolds, etc. From various causes they were apt to bulge out and fall (Ps. 62:3). In Ps. 80:12, R.V. (see Isa. 5:5), the psalmist says, "Why hast thou broken down her fences?" Serpents delight to lurk in the crevices of such fences (Eccl. 10:8; comp. Amos 5:19).