From BiblePortal Wikipedia

Webster's Dictionary [1]

(1): ( n.) A palmerworm.

(2): ( n.) Short for Palmer fly, an artificial fly made to imitate a hairy caterpillar; a hackle.

(3): ( n.) Short for Palmer fly, an artificial fly made to imitate a hairy caterpillar; a hackle.

(4): ( v. t.) One who palms or cheats, as at cards or dice.

(5): ( n.) A wandering religious votary; especially, one who bore a branch of palm as a token that he had visited the Holy Land and its sacred places.

(6): ( n.) A palmerworm.

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [2]

(Lat. palnifer, "a palm-bearer"), the name of one of those numerous classes of pilgrims (q.v.) whose origin and history form one of the most interesting studies in the social life of mediaeval Europe. Properly the Palmer designated a pilgrim who had performed the pilgrimage to the Holy Sepulchre at Jerusalem, and had returned or was returning home after the fulfilment of his vow. Palmers obtained that peculiar, name from their custom of carrying branches of the Oriental palm, in token of their accomplished expedition. On arriving at their home they repaired to the church to return thanks to God, and offered the palm to the priest, to be placed upon the altar. The palms so offered were frequently used in the procession of Palm-Sunday (q.v.). Even after the time of his return the religious character of the Palmer still continued; and although his office might be supposed to have ceased with the fulfilment of his vow, many Palmers continued their religious peregrinations even in their native country. They thus became a class of itinerant monks, without a fixed residence, professing voluntary poverty, observing celibacy, and visiting at stated times the most remarkable sanctuaries of the several countries of the West. Their costume was commonly the same as that of the ordinary pilgrim, although modified in different countries.

The Nuttall Encyclopedia [3]

The name given to a pilgrim to the Holy Land who had performed his vow, in sign of which he usually bore a palm branch in his hand, which he offered on the altar on his return home.