bead 
(bēd)
(bēd)n.
1.
a. A small, often round piece of material, such as glass, plastic, or wood, that is pierced for stringing or threading.
b. beads A necklace made of such pieces.
c. beads Roman Catholic Church A rosary.
d. often beads Obsolete A prayer.
2. A small, round object, especially:
a. A drop of moisture: beads of sweat.
b. A bubble of gas in a liquid.
c. A small metal knob on the muzzle of a firearm, such as a rifle, used for sighting.
3. A strip of material, usually wood, with one molded edge placed flush against the inner part of a door or window frame.
4. Architecture
a. A decoration consisting of a usually continuous series of small spherical shapes, as on a convex molding.
b. Beading.
5. A projecting rim or lip, as on a pneumatic tire.
6. A line of continuously applied ductile material, such as solder or caulking compound.
7. Chemistry A globule of fused borax or other flux used in a bead test.
tr. & intr.v. bead·ed, bead·ing, beads
Idiom: To furnish with or collect into beads.
draw/get a bead on
To take careful aim at.
[Middle English bede, rosary bead, prayer, from Old English bed, bedu, gebed, prayer; see gwhedh- in the Appendix of Indo-European roots.]