Which language has the most words?

Counting the total numer of words used in a language is complex as their are many variables. Comparisons are particularly difficult between alphabetic and non-alphabetic languages.

We can, however, use dictionary size when it comes to the principal European languages.

The Oxford English Dictionary

The OED is by far the largest dictionary. It has 23 volumes and defines 615,100 words.
❏ A similar German dictionary offers around 180,000 words. 
❏ A Russian language dictionary has around 160,000 words 
❏ A French edition has less than 150,000 words. 

What is a word? a surprisingly complex question