How to code a glide?

[John Burt]

I'm sorry to say that I don't even know the proper term for what I am
trying to do. I am setting some Georgian folksongs. Sometimes they end with
a descending glide on the last note (like an engine running down). On the
handwritten sheet music I have been using this is represented as a squiggly
descending line after the last note. I'd like to put that in my score, but
I have no idea how to code it. Does anyone have an idea?
John Burt