1
Core quality
Burdensome, demanding, or involving excessive effort, responsibility, or cost.
Example
Small firms found the reporting requirement onerous.
onerous
/ˈəʊnərəs/ · OH-nuh-rusadjective
Burdensome, demanding, or involving excessive effort, responsibility, or cost.
Use onerous to express this relationship precisely: burdensome, demanding, or involving excessive effort, responsibility, or cost.
What onerous Really Means
The word becomes easier to use when its closely related senses are separated and compared.
2
Attributive or predicative use
Use this adjective before a suitable noun or after a linking verb such as be or seem.
Example
Maintaining the remote station was costly and onerous.
3
Analytical distinction
Choose it when this exact descriptive quality matters; a related word may overlap without conveying the same trait.
Example
The agreement imposed onerous obligations on local councils.
Use onerous Naturally
Notice how the surrounding noun or clause reveals the exact shade of meaning.
Small firms found the reporting requirement onerous.
Maintaining the remote station was costly and onerous.
The agreement imposed onerous obligations on local councils.
Precision Matters
Onerous overlaps with several common words, but each carries a different emphasis.
onerous
vs.Means burdensome, demanding, or involving excessive effort, responsibility, or cost.
arduous
Means requiring sustained, difficult effort or endurance.
onerous
vs.Means burdensome, demanding, or involving excessive effort, responsibility, or cost.
strenuous
Means requiring or involving great physical or mental effort, energy, or exertion.
onerous
vs.Means burdensome, demanding, or involving excessive effort, responsibility, or cost.
prohibitive
Means so high in cost, difficulty, or burden that it prevents an action or use.
onerous
vs.Means burdensome, demanding, or involving excessive effort, responsibility, or cost.
mandatory
Means required by a rule, law, or authority; not optional.
Test onerous in Context
The rule imposed an excessive burden and effort.
1
The daily documentation rule became so ___ that volunteers began leaving the programme.