alexanders UK /ˌælɪɡˈzɑːndəz/US /ˌælɪɡˈzændɚz/ noun2 •Any of various umbellifers, often specifically Smyrnium olusatrum or Heracleum maximum, the cow parsnip. •(US, Canada) Various plants of genus Zizia or Angelica thought to resemble European alexanders.