flag

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

• noun A piece of cloth, usually rectangular, of distinctive color and design, used as a symbol, standard, signal, or emblem.
• noun National or other allegiance, as symbolized by a flag.
• noun A ship carrying the flag of an admiral; a flagship.
• noun A marking device, such as a gummed strip of paper, attached to an object to attract attention or ease identification; a tab.
• noun The masthead of a newspaper.
• noun Music A cross stroke that halves the value of a note to which it is added.
• noun A distinctively shaped or marked tail, as of a dog or deer.
• noun Computers A variable or memory location that stores true-or-false, yes-or-no information.
• transitive verb To mark with a flag or flags for identification or ornamentation.
• transitive verb To signal with or as if with a flag.
• transitive verb To signal to stop.
• noun A plant, such as an iris or cattail, that has long sword-shaped leaves.
• noun A flagstone.
• transitive verb To pave with slabs of flagstone.
• intransitive verb To lose vigor or strength; weaken or diminish.

from The Century Dictionary.

• To place a flag over or on: as, to flag a house.
• To signal or warn by the use of a flag: as, to flag a train or a steamboat.
• To decoy, as game, by waving some object like a flag to excite attention or curiosity.
• To tighten the seams of (a barrel) by means of flags. See flag, n. Encyc.
• noun Iris Florentina, with bluish-white flowers. See Iris and orris-root.
• noun A piece of thin, light fabric, especially bunting, usually rectangular and oblong or square, but sometimes triangular, notched, or otherwise varied in form, ranging from a few inches to several yards in dimensions, used hanging free from a staff to which it is attached or connected by one end, for many purposes, as a signal, symbol, cognizance, or standard, and differing in size, color, and emblematic marking or ornamentation, according to its intended use.
• noun The wing or pinion of a bird.
• noun In a glass-furnace having a grate-room in each end, a part of the bed intervening between the two grate-rooms and serving as a partition between them.
• noun In ornithology, the tuft of long feathers on the leg of falcons and most other hawks; the lengthened feathers on the crus or tibia.
• noun In sporting, the tail of a deer or of a setter dog.
• noun In music. See pennant and hook.
• noun The recognized standard or symbol of an extreme revolutionary party, or of those who seek social as well as political revolution or anarchy: as, the red flag of the Commune.
• noun A signal displayed by boats carrying powder, and by ships of war when they are shipping or discharging powder.
• noun A danger-signal in target-practice and on railways: used on the latter to bring trains to a stand.
• noun A piece of red flannel used as a lure for flsh.
• noun The bloody spout of a dying whale.
• To lay or pave with flags or flat stones.
• noun A piece of turf; a sod.
• noun A flat stone used for paving.
• noun A flake of snow.
• noun A tuft of coarse grass.
• To hang loosely and laxly; droop from weakness or weariness.
• To grow languid or less active; move or act more slowly; become feeble; droop; decline; fail: as, the spirits flag.
• To grow stale or vapid; lose interest or relish.
• To become careless or inefficient; slacken; halt.
• To flap; wave.
• Synonyms To languish, pine, sink, succumb.
• To cause or suffer to droop.
• To make feeble; enervate; exhaust.
• noun One of various endogenous plants with sword-shaped leaves, mostly growing in moist places; particularly, the common species of Iris, as the yellow flag or water-flag of England (I. Pseudacorus), the white flag (I. Germanica), and blue flags of the United States, as I. versicolor and I. prismatica.
• noun A groat; fourpence.
• noun A trade-name for the outer or distal portion of bristle, which is thinner and lighter than the basal portion.

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

• noun (Bot.) An aquatic plant, with long, ensiform leaves, belonging to either of the genera Iris and Acorus.