pollen

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The fine powderlike material whose individual grains contain the male reproductive cells of seed plants. Pollen is produced in the anther in angiosperms and in the male cone in gymnosperms.

from The Century Dictionary.

• noun A fine yellowish dust or powder produced in the anther of a flower (whence it is discharged when mature), which when magnified is found to consist of separate grains of definite size and shape; the male or fecundating element in flowering plants: the homologue of the microspore in cryptogams.
• To cover or dust with pollen; supply with pollen. Tennyson, Voyage of maeldune.

from the GNU version of the Collaborative International Dictionary of English.

• noun obsolete Fine bran or flour.
• noun (Bot.) The fecundating dustlike cells of the anthers of flowers. See Flower, and Illust. of Filament.
• noun (Bot.) a particle or call of pollen.
• noun a pollinium.
• noun a compartment of an anther containing pollen, -- usually there are four in each anther.
• noun a slender tube which issues from the pollen grain on its contact with the stigma, which it penetrates, thus conveying, it is supposed, the fecundating matter of the grain to the ovule.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A fine granular substance produced in flowers. Collective term for pollen grains or microspores produced in the anthers of flowering plants.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the fine spores that contain male gametes and that are borne by an anther in a flowering plant