Formidable
Formidable adjective - Requiring considerable physical or mental effort.
Usage example: running a marathon is a formidable undertaking
Onerous is a synonym for formidable in difficult topic. In some cases you can use "Onerous" instead an adjective "Formidable", when it comes to topics like heavy. popular alternative
Nearby Word: formidably
Onerous
Onerous adjective - Requiring much time, effort, or careful attention.
Usage example: building the scale model of the frigate was an onerous task
Formidable is a synonym for onerous in difficult topic. You can use "Formidable" instead an adjective "Onerous", if it concerns topics such as heavy, trying, weighty. popular alternative
Nearby Word: onerously
Mutual synonyms
Related pairs
Cite this Source
Onerous and Formidable. (2016). Retrieved 2026, August 16, from https://thesaurus.plus/related/formidable/onerous
Formidable & Onerous. N.p., 2016. Web. 16 Aug. 2026. <https://thesaurus.plus/related/formidable/onerous>.
Onerous or Formidable. 2016. Accessed August 16, 2026. https://thesaurus.plus/related/formidable/onerous.
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