levothyroxine /ˌli.voʊ.θaɪˈɹɑkˌsin/ noun1 •The levorotatory isomer of thyroxine (trademark Levothyroid, Levoxyl, Synthroid) that is administered in the form of its sodium salt C₁₅H₁₀I₄NNaO₄ in the treatment of hypothyroidism.
