: containing poisonous substances : poisonous
a toxic substance/compound
The fumes from that chemical are highly toxic.
Tests will be run to determine if the landfill is toxic.
—sometimes used figurativelya toxic [=very unpleasant] work environment
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“Toxic.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/toxic. Accessed 18 Jun. 2026.
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