fuss: what's 'toxic' mean?

Fuss is a word sponge, more so than even other kids.  He regularly drops things into casual conversation that make me go "where the hell did he pick THAT up?"

Like last night, when as we exited a chaotic bonfire/playdate he exclaimed "Yeah, let's get out of this anarchy!"

Because he rarely asks you what anything means it's hard to gauge the breadth of his dictionary, but little fireworks explosions like that are commonplace.  Where did he pick up anarchy? I mostly talk to him like I talk to anyone so it's not surprising he's heard it, but then he figured out appropriate usage on his own just from context?

Last night he surprised me with a language question while we were reading books.

"Dada, what's "toxic" mean?"
Formulating concrete, child-useful replies to questions you know you can answer but have never really needed to pin down is harder than you think, particularly after a long day and an evening spent enjoying a variety of excellent red wines.
"It means, uh....something that's gross...and really, really yucky."
"Oh." he replied.
There were a few moments of thoughtful silence, then he said
"So, it's like sand in your ice cream?"
"Yeah....it's a lot like sand in your ice cream."


My smart boy.