a large indefinite number
"a battalion of ants"
"a multitude of TV antennas"
"a plurality of religions"
a complete collection of similar things
"The museum's exhibit featured an impressive pack of rare artifacts from ancient Egypt."
a convenient package or parcel (as of cigarettes or film)
"He bought a pack of gum from the vending machine outside the station."
a sheet or blanket (either dry or wet) to wrap around the body for its therapeutic effect
"After his marathon, he applied a cold pack to his sore legs to reduce the swelling."
a bundle (especially one carried on the back)
"The hiker adjusted his heavy pack as he prepared to climb the steep mountain trail."
A bundle made up and prepared to be carried; especially, a bundle to be carried on the back, but also a load for an animal, a bale.
"The hikers carefully tied their gear into a tight pack before starting the steep climb."
In plain English: A pack is a group of animals that live and travel together.
"She asked me to help her carry the heavy pack of supplies up the mountain."
Usage: Use pack to refer to a collection of items bundled together for carrying or transport, such as a backpack filled with gear or a load for an animal. Avoid using it when you simply mean a group of people or animals unless they are specifically gathered into a tight bundle.
fill to capacity
"This singer always packs the concert halls"
"The murder trial packed the court house"
set up a committee or legislative body with one's own supporters so as to influence the outcome
"pack a jury"
treat the body or any part of it by wrapping it, as with blankets or sheets, and applying compresses to it, or stuffing it to provide cover, containment, or therapy, or to absorb blood
"The nurse packed gauze in the wound"
"You had better pack your swollen ankle with ice"
To put or bring things together in a limited or confined space, especially for storage or transport.
"The moving crew struggled to pack all our furniture into the small truck before sunset."
To make a pack of; to arrange closely and securely in a pack; hence, to place and arrange compactly as in a pack
"The hikers carefully packed their gear into the duffel bag so nothing would shift during the long trek."
In plain English: To pack means to put things into a bag or box so you can carry them somewhere.
"We need to pack our bags before the bus leaves."
Usage: Use "pack" to describe placing items tightly into a container, such as filling a suitcase with clothes before a trip. Avoid using it when simply gathering loose items without the intent of fitting them into a specific space.
The word "pack" comes from Old English and Middle Dutch roots meaning a bundle or collection of items. It entered modern usage with this same core sense of gathering things together for transport or storage.