'cat-toxic' originates from English, specifically the words 'cat' and 'toxic', where 'cat' meant 'domestic feline' and 'toxic' meant 'poisonous'.

'cat-toxic' is a modern English compound formed by combining the noun 'cat' and the adjective 'toxic'; it has arisen in contemporary usage (20th–21st century) to label substances dangerous to cats.

Initially, as a technical or descriptive compound, it simply meant 'poisonous to cats'; this core meaning has remained stable and is retained in current usage.