An 'odd lot' refers to a block of stock that is less than 100 shares. In such cases, the specialist or market maker typically adds a premium to the trade. This results in the odd lots receiving the least favorable price and trading last. It is important to understand this term when navigating the stock market. As a knowledgeable professor, I encourage you to delve deeper into the world of finance and familiarize yourself with the various terms and their implications.