universe

The word “universe” means all of space, time, matter, and energy that exists. In plain terms, everything that exists, or, more loosely, the entire scope of something being discussed.

“Universe” is pronounced YOO-nih-vurs (/ˈjunəˌvɝs/ in IPA).

Here is “universe” used in a sentence: “Scientists estimate the universe is roughly 13.8 billion years old.”

“Universe” is a noun.

The word “universe” comes from Latin. From Latin universum, "all things as a whole," from universus, literally "turned into one" — from unus ("one") plus versus ("turned").

“Universe” is a fairly common word in modern English, usually learned at around the B1 level.

“Universe” has 3 distinct senses listed in this dictionary. The most common is: all of space, time, matter, and energy that exists.

A galaxy is a single vast system of stars, gas, and dust bound together by gravity — our Sun sits in the Milky Way galaxy. The universe is everything that exists, containing billions of galaxies along with all space, time, matter, and energy. A galaxy is one small part of the whole universe.

Scientists estimate the universe is about 13.8 billion years old, dating from the Big Bang, when space, time, matter, and energy began expanding from an extremely hot, dense state. This age comes from measuring the expansion rate and studying the faint background radiation left over from that early moment.

The observable universe — the part we can in principle see — is roughly 93 billion light-years across, and it is still expanding. What lies beyond that boundary is unknown, and the universe as a whole may be far larger or even infinite. Its true full size cannot currently be measured.

The two words are often used interchangeably to mean everything that exists. 'Cosmos' tends to emphasise the universe seen as an ordered, harmonious whole, and carries a slightly more poetic or philosophical tone. 'Universe' is the more neutral, scientific term, but in most everyday contexts they mean the same thing.