constant

constant — adjective

1. Occurring again and again over a period of time, or continuing without stopping.

1.adjectiveB1
Definition

Occurring again and again over a period of time, or continuing without stopping.

Example

The constant noise from the construction site made it hard for Otis to concentrate on his homework.

attributive: constant + noun (noise)

Isabela grew tired of her brother's constant teasing about her new haircut.

Common collocations
  • constant noise
  • constant stream
  • constant pain
  • constant pressure
  • constant reminders
  • constant interruptions
Synonyms
  • continuous

    focuses on the unbroken nature, while 'constant' can also mean repeatedly occurring with gaps

  • persistent

    often carries a slightly negative connotation, like an unwelcome or annoying continuation

  • ongoing

    emphasises that something is still in progress, not necessarily frequent

Antonyms

Grammar Patterns

constant + noun

be + constant

Usage Note

Commonly modifies nouns for sounds, actions, or conditions that happen without a break (noise, crying, pain, stream, reminders, interruptions).

Common Mistakes

The constant rain had finally stopped' (using 'constant' for rain that lasted a while but eventually ended).
The steady rain had finally stopped
'constant' implies unbroken or endlessly repeated; 'steady' works better for continuous but finite events.

2. Remaining at the same level, amount, or rate without changing over time.

2.adjectiveB1
Definition

Remaining at the same level, amount, or rate without changing over time.

Example

The oven must be kept at a constant temperature for the cake to bake evenly.

collocation: constant temperature

Matthew's body weight stayed constant even though he started eating more vegetables.

Common collocations
  • constant temperature
  • constant speed
  • constant rate
  • remain constant
  • stay constant
  • keep constant
  • fairly constant
  • relatively constant
Synonyms
  • stable

    implies not only no change but also no risk of change; slightly less formal than 'constant'

  • steady

    focuses on evenness of movement rather than fixed value; works well for speed, progress, or rhythm

  • uniform

    suggests every part or unit is the same across time or space; more formal

Antonyms

Grammar Patterns

constant + noun

remain + constant

stay + constant

Usage Note

Frequently used with verbs like remain, stay, keep, and hold. Subject is typically a measurable quantity such as temperature, speed, price, level, or rate.

Common Mistakes

The recipe says to keep the water constant.
The recipe says to keep the water at a constant temperature.
'constant' needs a clear reference to the quality that stays unchanged (temperature, level, flow, etc.).

3. Faithful and dependable in a personal relationship, especially as a friend or co

3.adjectiveB2
Definition

Faithful and dependable in a personal relationship, especially as a friend or companion.

Example

Throughout the difficult years, Dario remained a constant friend who never let Sora down.

attributive: constant friend / constant companion

Grandfather's constant companion was an old sheepdog that followed him everywhere around the farm.

Common collocations
  • constant friend
  • constant companion
  • constant presence
Synonyms
  • faithful

    the most direct synonym; can be used both before a noun and after a linking verb with 'to'

  • loyal

    emphasises devotion and allegiance; slightly broader in use than 'constant'

  • steadfast

    more formal and literary; suggests firm determination in the face of difficulty

Antonyms
  • unfaithful

    breaks a promise of loyalty or commitment

  • fickle

    changes feelings or loyalty quickly and often

Grammar Patterns

constant + noun (person)

Usage Note

Almost always used before a noun (attributive position). This sense is mainly restricted to nouns referring to people (friend, companion) or personified things (presence, source of comfort). Distinguish from sense 1: a 'constant friend' is loyal, not merely someone who frequently visits.

Common Mistakes

She is constant to her husband.
She is a constant partner.
This sense of 'constant' is not used with the preposition 'to'; use 'faithful to' instead.

constant — noun

Word family

  • constantly
    adverbB1
  • constancy
    nounB2
  • inconstant
    adjectiveC1
  • inconstancy
    nounC2

Synonym discussion

Sense: adjective/1

Constant emphasises something that happens repeatedly or without a break — often with the nuance of being steady and expected, whether welcome or not ('constant noise from traffic'). Continuous stresses an unbroken chain in space or time, with no gaps at all ('a continuous line of cars'). Continual is similar but allows for brief gaps — it refers to something that recurs very frequently rather than being literally unbroken ('continual complaints'). Persistent adds a flavour of stubbornness or endurance, often describing something that refuses to go away ('persistent rumours'). Ongoing focuses on something still in progress, without implying frequency or intensity ('ongoing discussions'). In everyday conversation, 'constant' is the most versatile and natural choice for repeated occurrences.

constant ↗continuous ↗continual ↗persistent ↗ongoing ↗

Common collocations

Nouns

Adverbs

  • almost constant
  • fairly constant
  • relatively constant
  • roughly constant

Phrases

  • remain constant
  • stay constant
  • keep something constant
  • hold constant

Prepositions

  • constant across
  • constant throughout
  • constant in

Etymology

LatinFrenchEnglish

The word 'constant' entered English in the 14th century from Old French 'constant', which came from Latin 'constantem' (nominative 'constans'), the present participle of 'constare' — meaning 'to stand together, stand firm'. The Latin root breaks down into 'com-' (together) and 'stare' (to stand). The original sense was 'standing firm' or 'steadfast in mind', which later extended to 'unchanging in quantity' and 'happening repeatedly'. The mathematical sense developed in the 17th century as science and mathematics needed a precise term for fixed values.