Es más listo que el hambre
 

In English?

He is razor sharp.

When was the word "razor" first used in the English language? ;)

"Razor" is from Middle English "rasour" from Anglo-French "rasur", and apparently came into use
in English sometime after the Norman invasion of England in 1066. Merriam Webster gives 14th century.

In addition to Perikles' excellent suggestion, you can also say "to be as smart as they come."

I couldn't get the date in Merriam, just Middle English.

Yes, for us rasurar(afeitar) = shave

Thanks.

Presumably, that came from Latin rasus, past participle of radere: to scrape, shave, with associated words arrasar, arrastrar, rallar, ras, rascacielos, rascar, rasurar, etc.

Under Onelook Dictionary Search, Merriam Webster's Online Dictionary,
11th edition, says 14th century. That Onelook site is great...

Thanks for the link - it looks extremely useful. The reverse dictionary function could be useful as well. You type in your definition, and it comes up with suggestions for the word. Sometimes. :)

Correct, I imagine. :)

I would imagine also, that rasurar is closer to "ras" thence "rasar".