blow off

[hotmetal]

I didn't know it until an AmE speaker sent me the definition to add to our list.

Me neither, at least, not in this context.
I think it should be pointed out that in British English, "blow off" means something rather different! i.e. it is either a childish phrase meaning "to break wind", or an "adult" phrase denoting a sexual act…

Please be careful with our language out there folks!!