means A small marine crustacean prized as seafood; also slang for a small or short person.

from From Middle English shrimpe, meaning the little shellfish and, even then, a puny person — the two senses came bundled together. It likely traces back to a Germanic root suggesting something shrunken or contracted, a cousin of words like Middle High German schrimpfen, 'to wrinkle or shrivel.' So the insult isn't a later add-on: the shrimp was a byword for 'tiny thing' from the very beginning.