From Latin 'locusta,' meaning both 'locust' and 'lobster' — Romans saw a resemblance between the segmented creatures.
A large tropical grasshopper that periodically forms vast migratory swarms, stripping vegetation over wide areas and causing devastating agricultural damage.
From Latin 'locusta' (locust, also lobster), of uncertain deeper etymology. The same Latin word denoted both the swarming grasshopper and the marine crustacean, apparently because Romans saw a morphological resemblance between the two — both have segmented bodies, jointed legs, and antenna-like appendages. The word entered Old French as 'locuste' and thence into Middle English. The dual meaning persisted: 'lobster' derives from Old English 'loppestre,' but the Latin 'locusta' also contributed to some Romance words for lobster.