Definitions for palpusˈpæl pəs
Random House Webster's College Dictionary
an appendage attached to an oral part and serving as an organ of sense in insects, crustaceans, etc.
Origin of palpus:
1805–15; < NL; L palpus or palpum palm of the hand
a feeler; especially, one of the jointed sense organs attached to the mouth organs of insects, arachnids, crustaceans, and annelids; as, the mandibular palpi, maxillary palpi, and labial palpi. The palpi of male spiders serve as sexual organs. Called also palp. See Illust. of Arthrogastra and Orthoptera