This is the 5920th most frequent Spanish word.
tóxico
Harmful or poisonous.
Here, 'tóxico' is used as an adjective to describe a harmful or poisonous quality inherent in a substance.
Esa planta es tóxica si se consume.
That plant is toxic if ingested.
In this context, 'tóxico' metaphorically characterizes the negative emotional or relational effects within relationships.
Algunas relaciones pueden ser tóxicas para las personas involucradas.
Some relationships can be toxic for the people involved.
In this sentence, 'tóxico' describes the nature of gases that are harmful or hazardous to health.