methyldopa UK /ˌmiː.θʌɪlˈdəʊ.pə/US /ˌmɛθ.əlˈdoʊ.pə/ noun1 •The compound 3-(3,4-dihydroxyphenyl)-2-methyl-L-alanine, C₁₀H₁₃NO₄, which is used as an antihypertensive agent.