This seems strange to me. I'm sure everyone else already knew it.

From merriam-webster online
Main Entry: 4fallow
Function: adjective
Date: 15th century
1 : left untilled or unsown after plowing
2 : DORMANT, INACTIVE -- used especially in the phrase to lie fallow <at this very moment there are probably important inventions lying fallow>

I'm familiar with this definition. Here's the one that surprised me:

Main Entry: 3fallow
Function: transitive verb
Date: 15th century
: to plow, harrow, and break up (land) without seeding to destroy weeds and conserve soil moisture

It seems not contradictory, but also inconsonant.

After one fallows the ground it is no longer fallow.
Comments anyone?

k