are there other lisps with significant traction besides Clojure/Script?

ELisp

That is, it's the language nobody quite likes, but which is very hard to kill.

Racket?

dottedmag: elisp has big community but with “traction" I meant to imply fast growth & enthusiasm — not sure if that’s what traction actually means 😄

Scheme is pretty widely used in academia

Well then no.

But if traction is "widely used, whether in education or production", then Common Lisp, AutoLISP, ELisp, Scheme and Racket qualify. Maybe Guile as well, not sure.

Common Lisp is used a lot by cognitive modelling (psychology) type people (think ACT-R and friends)