Nettle \Net"tle\, n. [AS. netele; akin to D. netel, G. nessel, OHG. nezz["i]la, nazza, Dan. nelde, n["a]lde, Sw. n["a]ssla; cf, Lith. notere.]

(Bot.) A plant of the genus Urtica, covered with minute sharp hairs containing a poison that produces a stinging sensation. Urtica gracitis is common in the Northern, and U. cham[ae]dryoides in the Southern, United States. the common European species, U. urens and U. dioica, are also found in the Eastern united States. U. pilulifera is the Roman nettle of England.

Note: The term nettle has been given to many plants related to, or to some way resembling, the true nettle; as:

Australian nettle, a stinging tree or shrub of the genus Laportea (as L. gigas and L. moroides); -- also called nettle tree.

Bee nettle, Hemp nettle, a species of Galeopsis. See under Hemp.

Blind nettle, Dead nettle, a harmless species of Lamium.

False nettle (B[ae]hmeria cylindrica), a plant common in the United States, and related to the true nettles.

Hedge nettle, a species of Stachys. See under Hedge.

Horse nettle (Solanum Carolinense). See under Horse.

nettle tree.
   (a) Same as Hackberry.
   (b) See Australian nettle (above).

Spurge nettle, a stinging American herb of the Spurge family (Jatropha urens).

Wood nettle, a plant (Laportea Canadensis) which stings severely, and is related to the true nettles.

Nettle cloth, a kind of thick cotton stuff, japanned, and used as a substitute for leather for various purposes.

Nettle rash (Med.), an eruptive disease resembling the effects of whipping with nettles.

Sea nettle (Zo["o]l.), a medusa.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Dead letter.
   (a) A letter which, after lying for a certain fixed time uncalled for at the post office to which it was directed, is then sent to the general post office to be opened.
   (b) That which has lost its force or authority; as, the law has become a dead letter.

Dead-letter office, a department of the general post office where dead letters are examined and disposed of.

Dead level, a term applied to a flat country.

Dead lift, a direct lift, without assistance from mechanical advantage, as from levers, pulleys, etc.; hence, an extreme emergency. ``(As we say) at a dead lift.'' --Robynson (More's Utopia).

Dead line (Mil.), a line drawn within or around a military prison, to cross which involves for a prisoner the penalty of being instantly shot.

Dead load (Civil Engin.), a constant, motionless load, as the weight of a structure, in distinction from a moving load, as a train of cars, or a variable pressure, as of wind.

Dead march (Mus.), a piece of solemn music intended to be played as an accompaniment to a funeral procession.

Dead nettle (Bot.), a harmless plant with leaves like a nettle (Lamium album).

Dead oil (Chem.), the heavy oil obtained in the distillation of coal tar, and containing phenol, naphthalus, etc.

Source: Webster's Revised Unabridged Dictionary (1913)