Word of the Day


© BrandXPictures/ Jupiter Images


1. poisonous and harmful to people, animals, or the environment

2. used to describe a loan or other financial agreement which causes very serious business problems for a bank or financial organization

3. used about a subject on which opinion is so strongly divided that it is hard to have a reasonable discussion about it

4. very bad, unpleasant or harmful

View the full definition in the Macmillan Dictionary.

Origin and usage

The adjective toxic comes from a medieval Latin word ‘toxicus’ meaning ‘poisoned’. Its first attested use in English comes from the works of the gardener and diarist John Evelyn and dates from 1664. The related noun toxicity dates from the late 19th century, as does the noun toxin meaning ‘poison’. The financial meanings date from the 1990s.


While the adjective toxic is still used overhwelmingly to refer to things that are literally poisonous, its meanings and uses have expanded considerably in recent years. The financial crisis of 2008 brought terms like toxic assets and toxic debt to the fore. A toxic subject is one that is so contentious that it is almost impossible to talk about calmly, while a toxic debate involves such a subject. In the field of human relationships, meanwhile, we have toxic relationships, marriages, emotions and stress. The #Me Too movement has popularized the term toxic masculinity to such a degree that it gets 11.5 million hits in a Google search, having been barely used outside specialist discourse in psychology and gender studies until very recently.


“There was a time when idealistic folksingers such as myself believed that Reality TV was a programming vogue that would peak and recede, leaving only its hardiest show-offs. Instead, it has metastasized like toxic mold, filling every nook and opening new crannies.”
(James Wolcott, journalist)

Related words

noxious, poisonous, lethal

Browse related words in the Macmillan Thesaurus.

About the author

Macmillan Dictionary

Macmillan Dictionary

Leave a Comment