# density

Pronunciation: US say "DEN-suh-tee" /ˈdɛn.sə.ti/; UK say "DEN-si-tee" /ˈdɛn.sɪ.ti/

## Noun

1. A measure of how much mass is contained in a given unit of volume.
   - Simple: How much mass is packed into a certain amount of space.
   - _Engineers compared the density of several alloys before choosing the lightest one._
   - _Seawater has a slightly higher density than fresh water because of the dissolved salts._
2. A ratio relating an amount of something to the space, area, or extent over which it is spread.
   - Simple: How much of something there is in a given amount of space or area.
   - _Urban planners track population density to decide where new schools are needed._
   - _The forest's tree density dropped sharply in the years after the wildfire._
3. The relative likelihood that a continuous random variable takes a given value, expressed as probability per unit of the range.
   - Simple: A number showing how likely each possible value is, for something that can fall anywhere in a range.
   - _The analyst plotted the density to see where the measurements clustered._
   - _For a normal distribution, the density peaks at the mean and tapers toward the tails._

## Noun

4. Slowness or dullness of mind; stupidity. *(dated)*
   - Simple: The quality of being slow to think or understand.
   - _The foreman despaired at the density of his new apprentice, who grasped nothing he was shown._
   - _Her density in matters of money cost the family dearly over the years._

## Origin

This word was borrowed from Middle French "densité" or Latin "densitas," and is formed from "dense" plus the suffix "-ity."

Source: DictionaryAI, https://dictionaryai.com/define/density (written from Wiktionary data, CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/).