crown of thorns (Noun) — Any affliction that causes great suffering. ex. "he bears his afflictions like a crown of thorns"
crown of thorns (Noun) — Somewhat climbing bushy spurge of Madagascar having long woody spiny stems with few leaves and flowers with scarlet bracts.
crown of thorns (Noun) — A mock crown made of thorn branches that Roman soldiers placed on Jesus before the Crucifixion.