Pronunciation: [sˈakt ˈa͡ʊt] (IPA) 
The word "sacked out" is often spelled with a "c" instead of a "k" as it can be confusing. The correct spelling is "sacked out" and is pronounced as /ˈsæktaʊt/. The word refers to being exhausted or asleep, usually after an exerting day or activity. It is a colloquialism and commonly used in informal settings. Spell-check may correct the spelling to "sacked" or "packed," but the correct spelling is with a "k".
"Sacked out" is an colloquial idiom used to describe a state of deep sleep or extreme exhaustion. The phrase "sacked" originates from the word "sack," which refers to a bag, often made of coarse material, used for carrying items. In this context, being "sacked out" implies being completely and heavily settled or bundled up, as if being enveloped in a sack. The use of "sacked" denotes being enveloped or enclosed in a comfortable and relaxed manner, resembling the experience of being completely enclosed in a sack, which can be seen as a metaphorical representation of serene slumber.
This term is commonly used in casual conversations to describe someone who is in an intense and uninterrupted state of sleep, often following a physically or mentally exhausting activity or while recovering from such exertion. Alternatively, it can also convey a sense of being excessively fatigued, as if someone has reached the point of collapsing from exhaustion. The phrase is often employed to emphasize the depth and intensity of one's sleep or tiredness.
Additionally, "sacked" can also connote laziness or lack of motivation, specifically in the phrase "sacking out," which denotes idling or wasting time doing nothing productive. However, in the context of being "sacked out," the predominant meaning refers to a state of deep rest or extreme fatigue.
The phrase "sacked out" originated in American English and is believed to have emerged in the mid-20th century, specifically in the 1940s.
The term "sacked" is derived from the noun "sack", which refers to a large bag made of coarse material like burlap or sackcloth. In the context of "sacked out", it alludes to the act of sleeping or resting in a manner similar to being inside a bag or sack.
The phrase likely emerged as part of the vernacular of American soldiers during World War II. It may have been derived from the image of soldiers finding makeshift places to sleep while on the move or in field camps, using sacks or bags filled with straw or other materials as bedding.
