Is it correct to say "the last word but three"?

How can I refer to the bold word in the following text?

Lorem ipsum dolor sit amet, ea usu erant laboramus, ut vocent consequuntur nec. Usu partem gloriatur ut, eam te quas legendos, est accumsan accusamus argumentum te.

Is it correct to say "the last word but three"? I am looking for a general and commonly-used-by-people term.

Lorem ipsum dolor sit amet, ea usu erant laboramus, ut vocent consequuntur nec. Usu partem gloriatur ut, eam te quas legendos, est accumsan accusamus argumentum te.

Solution 1:

The term is preantepenultimate

That precedes or stands immediately before the antepenult; the last but three.

Oxford Dictionaries Online

Lest there be any confusion about what the above definition means, Wiktionary defines it as

Three before the end; fourth to last.

(Thanks to @Henry who informed me that I was not just making this up.)