aqueous

IPA/ˈeɪkwiəs/
KK[ˈekwiəs]IPA/ˈeɪkwiəs/

aqueous — adjective

  • aqueouspositive
  • more aqueouscomparative
  • most aqueoussuperlative

1. made up of water, holding water, or behaving in a way that resembles water — mos

1.adjectiveC2
Definition

made up of water, holding water, or behaving in a way that resembles water — most often used in scientific writing about solutions, mixtures, and natural fluids.

Example

The chemistry teacher poured salt into the beaker to make a simple aqueous solution.

common collocation: aqueous solution

Dr. Ito added a few drops of acid to the aqueous mixture in the beaker.

attributive use before a concrete noun

Common collocations
  • aqueous solution
  • aqueous humour
  • aqueous layer
  • aqueous phase
  • aqueous environment
  • dilute aqueous
Synonyms
  • watery

    everyday equivalent; preferred outside science writing

  • water-based

    used for products such as paints and inks; less formal

  • hydrous

    very formal; mainly mineralogy and chemistry

Antonyms
  • anhydrous

    scientific term meaning containing no water

  • oily

    everyday opposite when describing liquids

Grammar Patterns

aqueous + noun

Usage Note

Almost always attributive (before a noun) and almost always paired with a small set of nouns: solution, humour, environment, layer, phase, coating. Rare in everyday speech; learners will mainly meet it in chemistry, biology, or geology texts.

Common Mistakes

The soup tastes very aqueous.
The soup tastes very watery.
'aqueous' is a technical word; for everyday food or drink, use 'watery'.
The drink was aqueous and sweet.
The drink was watery and sweet.
outside science writing, native speakers prefer 'watery'.

Word family

Synonym discussion

Sense: adjective/1

These four adjectives all touch on the idea of water, but they sit in very different registers. 'Aqueous' is the most technical and is almost only seen in chemistry, biology, or geology — for example, an aqueous solution in a beaker. 'Watery' is the everyday word and often carries a slightly negative feeling about food or drink that is too thin, such as watery soup or watery coffee. 'Water-based' is a practical term used for products like paints, glues, and cleaners, telling buyers that water is the main ingredient. 'Hydrous' is even more formal than 'aqueous' and is mostly limited to describing minerals or compounds that contain water. Choose 'aqueous' for science writing, 'watery' for daily life, and 'water-based' for products.

aqueous ↗watery ↗water-basedhydrous ↗

Common collocations

Nouns

Adverbs

  • highly aqueous
  • predominantly aqueous

Phrases

  • aqueous solution
  • aqueous humour
  • aqueous phase
  • dilute aqueous mixture

Prepositions

  • aqueous in (composition)

Etymology

LatinMedieval LatinEnglish

Borrowed into English in the early 1600s from medieval Latin 'aqueus', built on Latin 'aqua' meaning water, plus the ending '-ous' that English uses to form adjectives. The same Latin root gives us aquarium, aquatic, and aqueduct, all of which keep the link to water visible.