'hippocampal' originates from New Latin, specifically the word 'hippocampus', where the Greek elements 'hippos' meant 'horse' and 'kampos' meant 'sea monster'.

'hippocampal' changed from the New Latin/Greek word 'hippocampus' and was formed in English by adding the adjective-forming suffix '-al' to refer to things relating to the 'hippocampus'.

Initially, 'hippocampus' referred to a seahorse or sea creature in Greek; later the anatomical brain structure was named 'hippocampus' for its shape, and 'hippocampal' evolved to mean 'relating to that brain structure'.