sack 1 
(săk)
(săk)n.
1.
a. A bag, especially one made of strong material for holding grain or objects in bulk.
b. The amount that a sack can hold: sold two sacks of rice.
2. also sacque A short loose-fitting garment for women and children.
3. Slang Dismissal from employment: finally got the sack after a year of ineptitude.
4. Informal A bed, mattress, or sleeping bag: hit the sack at 10:00.
5. Baseball A base.
6. Football A successful attempt at sacking the quarterback.
tr.v. sacked, sack·ing, sacks
Phrasal Verb: 1. To place into a sack: sacked the groceries.
2. Slang To discharge from employment: sacked the workers who were caught embezzling. See Synonyms at dismiss.
3. Football To tackle (a quarterback attempting to pass the ball) behind the line of scrimmage.
sack out Slang
To sleep.
[Middle English, from Old English sacc, from Latin saccus, from Greek sakkos, of Semitic origin; see śqq in the Appendix of Semitic roots.]
Word History: The ordinary word sack carries within it a few thousand years of commercial history. The Greeks got their word sakkos, "a bag made out of coarse cloth or hair," from the Phoenicians with whom they traded. The Phoenician word does not happen to be attested in any Phoenician writings that survive from antiquity, but words related to it can be found in the other Semitic languages, such as Hebrew śaq and Akkadian saqqu. The Greeks then passed the sack, as it were, to the Romans as Latin saccus, "a large bag or sack." The Latin word was then transmitted to the Germanic tribes with whom the Romans traded, and they gave it the form *sakkiz. (Similarly, many other languages of Europe, including Irish, Welsh, Albanian, Hungarian, Czech, Polish, and Russian, also have words derived from Greek sakkos or Latin saccus.) The speakers of Old English used two forms of the word, sæcc, meaning "sackcloth" and descending from Germanic *sakkiz, as well as sacc, meaning "a sack, a bag" and borrowed directly from Latin. The second Old English form is the ancestor of our sack.