Odd Lot

Also called board lot. An order of trading 100 (or hundreds) shares of a security. It is opposed to odd-lot order where the order is less than 100 shares of security. Historically, some brokers charge higher commissions for odd-lot orders. But it is not clear if brokers still charge more for odd-lot orders.
See more at Wikipedia.org...

A trading  order for less than 100 shares of stock. Compare round lot.

A transaction involving fewer shares than in a "round" lot, which for most stocks is 100 shares.