hardtack

“Hardtack is an old-fashioned type of bread or cracker that sailors used to bring with them during long voyages. The taste and texture of hardtack wasn’t popular, but it lasted a long time without spoiling.

If you take a close look at the word hardtack, you’ll have a clear sense of how sailors felt about having to eat it day after day. The hard part is accurate — it was so dry and tough that it was difficult to bite. Tack once meant “food,” but in dialect it was specifically “bad food.” Hardtack had many alternate names, including “soda crackers” and “sea biscuits,” but also “dog biscuits” and “molar breakers.” “

from dictionary.com

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