noun The·si·um \ˈthēsēəm, thə̇ˈsīəm\

Definition of Thesium

  1. :  a large genus of Old World root-parasitic herbs of the family Santalaceae with small linear or scalelike leaves and diclinous flowers — see bastard toadflax

Love words? You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Join MWU now and get access to America’s largest dictionary, with:

  • 300,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

Origin and Etymology of thesium

New Latin, from Latin thesium, thesion bastard toad flax, from Greek thēseion, probably from neuter of thēseios of Theseus, from Thēseus Theseus, mythological Greek hero

Seen and Heard

What made you want to look up Thesium? Please tell us where you read or heard it (including the quote, if possible).


feeling or affected by lethargy

Get Word of the Day daily email!