salp Syllabification: (salp)Pronunciation: /salp/Definition of salp noun a free-swimming marine invertebrate related to the sea squirts with a transparent, barrel-shaped body. Several genera in the class Thaliacea, subphylum Urochordata Origin: mid 19th century: from French salpe, based on Greek salpē 'fish'salp in other Oxford dictionaries Definition of salp in the British & World English dictionary