Oxford Dictionary just released its Word of the Year for 2018, and they went with "toxic."
Sorry in advance for now having the Britney Spears song from years ago stuck in your head.
Oxford said toxic does the best job "reflecting the ethos, mood, or preoccupations of the passing year, and has lasting potential as a term of cultural significance."
"Toxic" DID come up a lot of different ways, from metaphorical use like "toxic political environment" and "toxic masculinity" to literal use like "toxic algae" and "toxic waste."
Oxford's runners up included gaslighting, incel, and overtourism.