The word "起码" is formed through a metaphorical extension from the concrete to the abstract, originating in the context of cargo handling and measurement. The character "起" means to start or raise, while "码" refers to a tally mark or numbered weight (like a counter). Historically, it related to loading goods onto a ship, where "起" meant to start loading and "码" indicated the marked tallies used to count the minimum number of items or weight required for a basic shipment or transaction. Thus, combining them created the concept of the "starting tally" or the lowest countable unit, which evolved metaphorically to mean "at the very least" or "minimum", conveying a baseline requirement or absolute lower limit.