Part 660

Let"ter*ing, n. 1. The act or business of making, or marking with, letters, as by cutting or painting.

2. The letters made; as, the lettering of a sign.

Let"ter*less (lt"tr*ls), a. 1. Not having a letter.

2. Illiterate. [Obs.] E. Waterhouse.

Let"tern (lt"trn), n. See Lecturn.

Let"ter*press` (-tr*prs`), n. Print; letters and words impressed on paper or other material by types; -- often used of the reading matter in distinction from the illustrations.

Letterpress printing, printing directly from type, in distinction from printing from plates.

Let"ter*ure (-r), n. Letters; literature. [Obs.] "To teach him letterure and courtesy." Chaucer.

Let"ter*wood` (-wd`), n. (Bot.) The beautiful and highly elastic wood of a tree of the genus Brosimum (B. Aubletii), found in Guiana; -- so called from black spots in it which bear some resemblance to hieroglyphics; also called snakewood, and leopardwood. It is much used for bows and for walking sticks.

Let"tic (lt"tk), a. (a) Of or pertaining to the Letts; Lettish. (b) Of or pertaining to a branch of the Slavic family, subdivided into Lettish, Lithuanian, and Old Prussian. -- n. (a) The language of the Letts; Lettish. (b) The language of the Lettic race, including Lettish, Lithuanian, and Old Prussian.

Let"tish (lt"tsh), a. Of or pertaining to the Letts. -- n. The language spoken by the Letts. See Lettic.

Let"trure (-trr), n. See Letterure. [Obs.] Chaucer.

Letts (lts), n. pl.; sing. Lett (lt). (Ethnol.) An Indo-European people, allied to the Lithuanians and Old Prussians, and inhabiting a part of the Baltic provinces of Russia.

Let"tuce (lt"ts), n. [OE. letuce, prob. through Old French from some Late Latin derivative of L. lactuca lettuce, which, according to Varro, is fr. lac, lactis, milk, on account of the milky white juice which flows from it when it is cut: cf. F. laitue. Cf. Lacteal, Lactucic.] (Bot.) A composite plant of the genus Lactuca (L. sativa), the leaves of which are used as salad. Plants of this genus yield a milky juice, from which lactucarium is obtained. The commonest wild lettuce of the United States is L. Canadensis.

Hare's lettuce, Lamb's lettuce. See under Hare, and Lamb. - - Lettuce opium. See Lactucarium. - - Sea lettuce, certain papery green seaweeds of the genus Ulva.

Let"u*a*ry (lt"**r), n. Electuary. [Obs.] Chaucer.

Let"-up` (lt"p`), n. [See Let to forbear.] Abatement; also, cessation; as, it blew a gale for three days without any let-up. [Colloq.]

Leuc- (lk-). Same as Leuco-.

||Leu`ca*den"dron (l`k*dn"drn), n. [NL., fr. Gr. leyko`s white + ||de`ndron tree.] (Bot.) A genus of evergreen shrubs from the Cape of ||Good Hope, having handsome foliage. Leucadendron argenteum is the ||silverboom of the colonists. || Leu*can"i*line (l*kn"*ln or -ln), n. [Leuc- + aniline.] (Chem.) A colorless, crystalline, organic base, obtained from rosaniline by reduction, and also from other sources. It forms colorless salts.

||Leu*chæ"mi*a (l*k"m*), n. [NL., fr. Gr. leyko`s white + a"i^ma ||blood.] (Med.) See Leucocythæmia. -- Leu*chæm"ic (l*km"k), a. ||[Written also leukæmia, leukæmic.] || { Leu"cic (l"sk), Leu*cin"ic (l*sn"k), } a. (Chem.) Pertaining to, or designating, an acid obtained from leucin, and called also oxycaproic acid.

Leu"cin (l"sn), n. [Gr. leyko`s white.] (Physiol. Chem.) A white, crystalline, nitrogenous substance formed in the decomposition of albuminous matter by pancreatic digestion, by the action of boiling dilute sulphuric acid, and by putrefaction. It is also found as a constituent of various tissues and organs, as the spleen, pancreas, etc., and likewise in the vegetable kingdom. Chemically it is to be considered as amido-caproic acid.

Leu"cite (l"st), n. [Gr. leyko`s white: cf. F. leucite.]

1. (Min.) A mineral having a glassy fracture, occurring in translucent trapezohedral crystals. It is a silicate of alumina and potash. It is found in the volcanic rocks of Italy, especially at Vesuvius.

2. (Bot.) A leucoplast.

Leu*cit"ic (l*st"k), a. (Min.) Containing leucite; as, leucitic rocks.

Leu"ci*toid (l"s*toid), n. [Leucite + -oid.] (Crystallog.) The trapezohedron or tetragonal trisoctahedron; -- so called as being the form of the mineral leucite.

{ Leu"co- (l"k-), Leuc- (lk- ). } [Gr. leyko`s white.] A combining form signifying white, colorless; specif. (Chem.), denoting an extensive series of colorless organic compounds, obtained by reduction from certain other colored compounds; as, leucaniline, leucaurin, etc.

Leu"co*cyte (l"k*st), n. [Leuco- + Gr. ky`tos a hollow vessel.] (Physiol.) A colorless corpuscle, as one of the white blood corpuscles, or those found in lymph, marrow of bone, connective tissue, etc.