Onerous

/ˈoʊnərəs/

adjectiveC1

Definition

Onerous describes tasks, duties, or responsibilities that feel hard to do because they take a lot of time, effort, or cause stress. It often means something is not just difficult but also a burden or heavy to carry mentally or physically.

Was this helpful?

Make this word yours

Save to Collection

In your personal learning flow

See It in Action

Difficult and heavy in work or responsibility

  • The job of managing the entire project was onerous and stressful.
  • Filling out all the paperwork was an onerous task.
  • He found the legal contract's conditions very onerous.

Causing a feeling of burden or hardship

  • The onerous rules made it hard for the small business to succeed.
  • She felt the care of her sick relative was an onerous responsibility.

Make It Stick

  • Think of "onerous" like "hard," but much stronger—it’s not just a little difficult, it feels like a heavy load you must carry
  • Picture carrying a large, heavy backpack full of books that makes walking slow and tiring
  • It's the feeling you get when you have many difficult chores or a job that makes you very tired and stressed
  • Sounds like "OWN-uh-rus" → Imagine someone saying "Oh, I own this heavy task" because it feels like a big responsibility you must carry
  • Think of a character in a story who must do a difficult, long task that feels like a punishment or heavy duty
  • NOT like "easy" or "simple" tasks, but tasks that weigh you down and take a lot of effort
  • NOT like "fun" or "light" activities; onerous means serious and tiring work

Try Other Words

  • Burdensome: causing worry or difficulty (Use when the task feels like a heavy weight you must carry mentally or physically)
  • Demanding: needing a lot of effort or attention (Use when the task requires a lot of energy or focus)
  • Taxing: physically or mentally tiring (Use when the task makes you feel very tired)
  • Challenging: difficult but possibly positive (Use when the difficulty is seen as a test or opportunity)

Unboxing

  • Word parts: (no clear prefix or suffix, but "-ous" means "full of" or "having the quality of")
  • Etymology: From Latin "onerosus," from "onus" meaning "burden" or "load"
  • Historical development: Used since the 1600s in English to describe something that carries a heavy burden or responsibility
  • Modern usage: Used mostly in formal or written English to describe difficult duties or responsibilities that feel heavy or stressful

Reflect & Connect

Can a task be important but also onerous? How do people handle such tasks?
How does knowing the word onerous help you describe your own experiences with difficult responsibilities?

Fill in the blanks

1.The project became onerous because it required ___ hours and ___ attention to detail.
2.She found the legal agreement onerous due to its ___ conditions and strict ___.
3.Unlike simple chores, onerous tasks often cause ___ and require ___ effort.
4.When a responsibility is onerous, people may feel ___ or ___ because of the pressure.
5.The manager gave him an onerous duty that was both time-consuming and ___.
6.Onerous tasks are often ___ by people who want to avoid stress or heavy workloads.
7.Even though the job was onerous, he accepted it because of its ___ importance.