Bottom-up and Grass roots

Bottom-up adjective - Of an approach to a problem that begins with details and works up to the highest conceptual level.

Grass roots and bottom-up are semantically related. In some cases you can replace phrase "Grass roots" with "Bottom-up", this phrases are similar.

Grass roots noun - The common people at a local level (as distinguished from the centers of political activity).

Bottom-up and grass roots are semantically related. You can use "Bottom-up" instead an adjective phrase "Grass roots".