1. Root

 deru̯, dreu̯

2. Lexical meanings

 EN: be firm, solid, steadfast, tree, wood

3. Comparative evidence

4. Formally comparable roots

 1.der, 1.dreh₂, 1.drem, 2.der, 2.dreh₂, 2.drem, derkh₂, derkʷh₂, derḱh₂, derbʰ, derd, derdʰ, derh₁gʰ, derh₂gʰ, derh₃gʰ, derh₂, derk, derḱ, dreb, dret, dregʰ, dreh₁, drep, dreu̯, dreu̯g, dreu̯h₁, dreu̯h₂, dreu̯h₃, dreǵʰ

5. Formally/Semantically comparable roots

6. Revised root variants

7. Comments

8. References

Watkins 2011 = Watkins, Calvert. 2011. The American heritage dictionary of Indo-European roots. 3rd revised ed. Boston, New York: Houghton Mifflin Harcourt.