Like-Kind Property
  
See: Life-Kind Exchange.
A high school cafeteria: jocks sit with jocks; drama kids sit with drama kids; etc. Everyone self-softed by like-kind.
Now, to the financial world. The term refers to two assets that resemble each other enough that they can become almost indistinguishable, at least for tax purposes.
This $650,000 house vs. that $650,000 house. $10,000 invested in this stock vs. $10,000 invested in that stock. For tax purposes, these pairings would be considered like-kind property.