sack

On obvious quarterback runs (such as quarterback draws or sneaks), if the QB is tackled behind the line of scrimmage, it is NOT a sack. Sacks are limited to losses in passing plays (or if the quarterback attempts to scramble when unable to pass the ball). Sacks are also credited if the quarterback is chased out of bounds behind the line of scrimmage.

Individually, the defensive player who sacks the quarterback is credited with a sack. In the case of two players, each is credited with 1/2 a sack (sacks are not split beyond 1/2s).

The sack became an official NFL stat in 1982. The all-time career sack leader is Reggie White, with 198. The NFL single-season sack record is held by Mark Gastineau (22 for the New York Jets in 1984).

"Sack" can be used as a noun or a verb ("to sack the quarterback").

A sort of fortified white wine, likely relatively sweet, imported from Spain and the Canary Islands, very popular in England during the 16th and 17th centuries. Matured in wooden barrels for times not upwards of two years. Sherry is its modern equivalent, its name originating with Sherris sack imported from Jerez de la Frontera. Shakespeare's Falstaff was a big fan - the wine is namedropped twenty-one times in connection to him in Henry IV, Part 1.

Samuel Pepys's diary makes mention of it, too, in its October 15, 1665 entry:

By and by by appointment comes Mr. Povy’s coach, and, more than I expected, him himself, to fetch me to Brainford: so he and I immediately set out, having drunk a draft of mulled sacke;

There's some confusion about where the term sack comes from. The OED places its earliest English use in the early 16th century as wyne seck, and elaborates on possible associations with the French vin sec ('dry wine') and the German sekt, though with some uncertainty. The Oxford Companion to Wine pitches a different theory by proposing origins in the use of sarcas to mean exports of wine, from the Spanish sacar ('to draw out').

References:
OED
http://www.winepros.com.au/jsp/cda/reference/oxford_entry.jsp?entry_id=2790
http://www.pepysdiary.com/archive/1665/10/15/
http://en.wikipedia.org/wiki/Sack_(wine)
Henry IV

Sack (?), n. [OE. seck, F. sec dry (cf. Sp. seco, It secco), from L. siccus dry, harsh; perhaps akin to Gr. , Skr. sikata sand, Ir. sesc dry, W. hysp. Cf. Desiccate.]

A name formerly given to various dry Spanish wines.

Shak.

Sack posset, a posset made of sack, and some other ingredients.

© Webster 1913.

Sack, n. [OE. sak, sek, AS. sacc, saecc, L. saccus, Gr. from Heb. sak; cf. F. sac from the Latin. Cf. Sac, Satchel, Sack to plunder.]

1.

A bag for holding and carrying goods of any kind; a receptacle made of some kind of pliable material, as cloth, leather, and the like; a large pouch.

2.

A measure of varying capacity, according to local usage and the substance. The American sack of salt is 215 pounds; the sack of wheat, two bushels.

McElrath.

3. [Perhaps a different word.]

Originally, a loosely hanging garnment for women, worn like a cloak about the shoulders, and serving as a decorative appendage to the gown; now, an outer garment with sleeves, worn by women; as, a dressing saek.

4.

A sack coat; a kind of coat worn by men, and extending from top to bottom without a cross seam.

5. Biol.

See 2d Sac, 2.

<--6. [Colloq.] Bed. -->

Sack bearer Zool.. See Basket worm, under Basket. -- Sack tree Bot., an East Indian tree (Antiaris saccidora) which is cut into lengths, and made into sacks by turning the bark inside out, and leaving a slice of the wood for a bottom. -- To give the sack to ∨ get the sack, to discharge, or be discharged, from employment; to jilt, or be jilted. [Slang]<-- hit the sack, go to bed. -->

© Webster 1913.

Sack, v. t.

1.

To put in a sack; to bag; as, to sack corn.

Bolsters sacked in cloth, blue and crimson. L. Wallace.

2.

To bear or carry in a sack upon the back or the shoulders.

© Webster 1913.

Sack, n. [F. sac plunder, pillage, originally, a pack, packet, booty packed up, fr. L. saccus. See Sack a bag.]

the pillage or plunder, as of a town or city; the storm and plunder of a town; devastation; ravage.

The town was stormed, and delivered up to sack, -- by which phrase is to be understood the perpetration of all those outrages which the ruthless code of war allowed, in that age, on the persons and property of the defenseless inhabitants, without regard to sex or age. Prescott.

© Webster 1913.

Sack, v. t. [imp. & p. p. Sacked (?); p. pr. & vb. n. Sacking.] [See Sack pillage.]

To plunder or pillage, as a town or city; to devastate; to ravage.

The Romans lay under the apprehension of seeing their city sacked by a barbarous enemy. Addison.

© Webster 1913.