Rathole

1. The act of taking small profits in a poker game, leaving the table, and returning to the same game with the minimum buyin.

Etiquette

In live poker, ratholing, sometimes called "going south" is prohibited, and there are rules (see Table Stakes) to prevent it.

In online poker, it is more common since ratholers (also known as "shorstackers") can take advantage of the greater number of tables to accomplish their goals.