levothyroxine

noun
le·​vo·​thy·​rox·​ine
variants: or British laevothyroxine \ ˌlē-​vō-​thī-​ˈräk-​ˌsēn, -​sən How to pronounce laevothyroxine (audio) \

Medical Definition of levothyroxine

: the levorotatory isomer of thyroxine that is administered in the form of its sodium salt C15H10I4NNaO4 in the treatment of hypothyroidism — see levothroid, levoxyl, synthroid