> but I would define "dead" as "not being used for starting new projects with intent for these projects to be used in practice"
> I'd consider Clojure activity as evidence that "Lisp may be dead but its descendents live on"
except that common/emacs lisp or scheme is certainly not dead by any measure lol
If a language is being widely used in specific existing 'legacy' projects and for people learning it to get a job in their maintenance (e.g. COBOL?), then I'd say it's dead. If during the last five years every organization considering what language to use for their new production system (as opposed to someone's toy project or learning project) chose something else, then that language apparently has no valid niche remaining and is effectively dead, being chosen only due to legacy/compatibility reasons.
Also, I'm not sure whether I'd equate Clojure with Lisp - I'd treat it as a separate language/ecosystem evolved from Lisp as it was commonly understood; I'd consider Clojure activity as evidence that "Lisp may be dead but its descendents live on".