• Webster's Revised Unabridged Dictionary
    • n Palpus (Zoöl) 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.
    • ***
Century Dictionary and Cyclopedia
    • n palpus In zoology: One of the jointed organs attached to the labium and maxillæ of insects; a feeler. The labial palpi are two in number, rising either from the ligula or from the edge of the mentum; the maxillary palpi are placed one on the outer side of each maxilla. Besides these, certain Coleoptera have a second two-joined palpiform appendage on each maxilla, formed by a modification of the galea or external lobe. The palpi vary much in form and in the number of joints, which is never more than six; they are sometimes aborted or entirely absent, as in the Hemiptera. In the Lepidoptera this term is commonly restricted to the large labial palpi, the much smaller maxillary ones being distinguished as palpuli. The palpi are supposed by some to be organs of taste or touch. In the spiders the maxillary palpi are greatly developed, forming the pedipalps; these, in the scorpions, become chelate appendages, commonly called the front legs. Small palpi are also developed from the mandibles and maxillæ of certain crustaceans. See cuts under Acarida, Allorhina, Erotylus, galea, Hymenoptera, Insecla, Meloë, mosquito, mouth-part, Nymphon, Araneida, scorpion, Buthus, Cryptophialus, and Podophthalmia.
    • n palpus One of the fleshy lobes at the sides of the mouth of acephalous mollusks. More fully called labial palpus. See second cut under Lamellibranchiata.
    • ***


Webster's Revised Unabridged Dictionary
NL. See Palp


In literature:

The palpus, too, on this side was turned back to correspond to the direction of the legs nearest it.
"Studies in the Psychology of Sex, Volume 3 (of 6)" by Havelock Ellis
Labipalp: a labial palpus.
"Explanation of Terms Used in Entomology" by John. B. Smith
The galea sometimes forms a palpus-like appendage.
"Our Common Insects" by Alpheus Spring Packard
When you touch him, he draws up slowly one leg after another, or moves a palpus feebly.
"Children's Literature" by Charles Madison Curry
Terminal joint of each palpus less than a third as long as the middle joint.
"Butterflies Worth Knowing" by Clarence M. Weed
When you touch him, he draws up slowly one leg after another, or moves a palpus feebly.
"Insect Stories" by Vernon L. Kellogg