noun

• The act of conducting or carrying out (business, negotiations, plans).
• A deal or business agreement.
• An exchange or trade, as of ideas, money, goods, etc.
• (finance) The transfer of funds into, out of, or from an account.
• (computing) An atomic operation; a message, data modification, or other procedure that is guaranteed to perform completely or not at all (e.g. a database transaction).
• (especially in plural) A record of the proceedings of a learned society.
• (transactional analysis) A social interaction.