[fens] 
noun, verb, fenced, fenc⋅ing.| 1. | a barrier enclosing or bordering a field, yard, etc., usually made of posts and wire or wood, used to prevent entrance, to confine, or to mark a boundary. |
| 2. | Informal. a person who receives and disposes of stolen goods. |
| 3. | the place of business of such a person. |
| 4. | the act, practice, art, or sport of fencing. |
| 5. | skill in argument, repartee, etc. |
| 6. | Machinery. a guard or guide, as for regulating the movements of a tool or work. |
| 7. | Carpentry. a slotted guide used esp. with a framing square to lay out cuts on rafters and staircase strings. |
| 8. | Archaic. a means of defense; a bulwark. |
| 9. | to enclose by some barrier, establishing exclusive right to possession: to fence a farm. |
| 10. | to separate by or as by a fence or fences (often fol. by in, off, out, etc.): to fence off a corner of one's yard; to fence out unwholesome influences. |
| 11. | to defend; protect; guard: The president was fenced by bodyguards wherever he went. |
| 12. | to ward off; keep out. |
| 13. | Informal. to sell (stolen goods) to a fence. |
| 14. | Nautical. to reinforce (an opening in a sail or the like) by sewing on a grommet or other device. |
| 15. | to practice the art or sport of fencing. |
| 16. | to parry arguments; strive to avoid giving direct answers; hedge: The mayor fenced when asked if he would run again. |
| 17. | (of a horse) to leap over a fence. |
| 18. | Obsolete. to raise a defense. |
| 19. | mend one's fences, to strengthen or reestablish one's position by conciliation or negotiation: One could tell by his superficially deferential manner that he was trying to mend his fences. |
| 20. | on the fence, uncommitted; neutral; undecided: The party leaders are still on the fence. |
| fence (fěns) n.
v. tr.
[Middle English fens, short for defens, defense; see defense.] fenc'er n. |
fence
fence
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 optimised 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 optimising compilers] Any technique, usually exploiting knowledge about the compiler, that blocks certain optimisations. 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 optimiser's register-colouring info" can be expressed by the shorter "That's a fence procedure".
[The Jargon File]
(1999-01-08)
Fence
(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).
fence
In addition to the idioms beginning with fence, also see mend one's fences; on the fence; straddle the fence.
