Answer: esperanto

AnswerCrossword Clue
ESPERANTO

Stalin called it "the language of spies"

ESPERANTO

Stalin's "language of spies"

ESPERANTO

Artificial language

ESPERANTO
Professor Zamenhof's invention
ESPERANTO
You'll find it in 180,000+ Wikipedia articles
ESPERANTOIt means "one who hopes"
ESPERANTOUniversal language.
ESPERANTOOdd language.
ESPERANTOArtificial language.
ESPERANTOInternational language.
ESPERANTOL.L. Zamenhof's creation
ESPERANTO"Saluton! Kiel vi fartas?," e.g.
ESPERANTOLingua franca, for some
ESPERANTOPerson ate boiled tongue (9)
ESPERANTOLanguage in which plurals are formed by adding -oj
ESPERANTOThe 1965 William Shatner film "Incubus" is in it
ESPERANTOIt has just 16 rules of grammar
ESPERANTOOne prates oddly in a language few can understand (9)
ESPERANTOLanguage devised in 1887
ESPERANTOLanguage with no irregular verbs
ESPERANTO"Please" and "thank you" are "bonvolu" and "dankon" in it
ESPERANTO"I love you" is "Mi amas vin" in it
ESPERANTOLanguage in which plural adjectives end in -aj