The story
Probably from (de)carb(oxylase) + i(nhibitor) + -dopa (“dopamine derivative”).
Etymology from Wiktionary, CC BY-SA 4.0.
carbidopa
Today it means: A drug C₁₀H₁₄N₂O₄·H₂O that inhibits decarboxylation of ʟ-dopa in tissues outside the brain and that is administered with ʟ-dopa in the treatment of Parkinson's disease to increase the amount of ʟ-dopa available for transport to the brain. Full definition →