Definition of Notwithstanding: Notwithstanding (preposition, adverb, conjunction): In spite of, despite something. Synonyms: despite, in spite of, although, however Antonyms: because of, due to, thanks to Memory Tip: Think of “notwithstanding” as meaning “despite” or “in spite of,” like when you do something even though there’s an obstacle, you keep going notwithstanding the challenge. Conversation…