What is the linguistic meaning of tajweed? What is lahan jalee and lahan khafee?

What is the linguistic meaning of tajweed?

What is lahan jalee and lahan khafee?

Answer

Assalaam alaikum. 

The linguistic meaning of tajweed is: Betterment. 
The applied definition of tajweed is:  Articulating every letter from its articulation point and giving the letter its rights and dues of characteristics. 

 is an obvious and clear mistake. It is a mistake that occurs in the pronunciation of the that affect the accuracy of the reading.

 is an obscured and hidden mistake.  It is a mistake that enters the reading but is only heard and known by an accomplished reader.  It is not a mistake that leads to a change in the meaning, or language, or grammar. 

Wa assalaam