left untilled or unsown after plowing

to work by plowing, sowing, and raising crops : cultivate

1: left untilled or unsown after plowing
[M-W’s Col. Dic.]

“till” consists of three stages: plowing, sowing, and raising. The definition of “fallow” says left ‘untilled’ after plowing although ‘plowing’ in itself is one of the stages of tilling. If a land is left untilled, then that would mean that no plowing has been carried on.

My question is concerned about how words are used in sentences. It seems that it is not always compulsory to use full definitions of words. One can only use a part of a definition but one has to add further information to make the meaning clear. e.g. In “left untilled after plowing”, only a selective part of the definition of ‘till’ is used and that part only consists of one stage, plowing. What is your opinion on this? Please let me know. Thanks.