Definition of ironwort in US English:

ironwort

noun

  • Any of various small shrubs or herbs constituting the genus Sideritis (family Lamiaceae (Labiatae)), native chiefly to the Mediterranean and used medicinally; frequently with distinguishing word. Also: any of several hemp-nettles (genus Galeopsis), especially the common hemp-nettle, G. tetrahit, formerly used to treat wounds (now rare).

Origin

Mid 16th century; earliest use found in William Turner (d. 1568), naturalist and religious controversialist. From iron + wort, after classical Latin sidērītis siderite.

Pronunciation

ironwort

/ˈʌɪənwəːt/