Part 6482

<hw>Let"*up`</hw> <tt>(?)</tt>. <tt>n.</tt> <ety>[See <er>Let</er> to forbear.]</ety> <def>Abatement; also, cessation; <as>as, it blew a gale for three days without any <ex>let-up</ex></as>.</def> <mark>[Colloq.]</mark>

<h1>Leuc-</h1> <Xpage=845>

<hw>Leuc-</hw> <tt>(?)</tt><def>. Same as <er>Leuco-</er>.</def>

<h1>Leucadendron</h1> <Xpage=845>

<hw>Leu`ca*den"dron</hw> <tt>(?)</tt>, <tt>n.</tt> <ety>[NL., fr. Gr. <?/ white + <?/ tree.]</ety> <fld>(Bot.)</fld> <def>A genus of evergreen shrubs from the Cape of Good Hope, having handsome foliage. <spn>Leucadendron argenteum</spn> is the <stype>silverboom</stype> of the colonists.</def>

<h1>Leucaniline</h1> <Xpage=845>

<hw>Leu*can"i*line</hw> <tt>(?)</tt>, <tt>n.</tt> <ety>[<ets>Leuc-</ets> + <ets>aniline</ets>.]</ety> <fld>(Chem.)</fld> <def>A colorless, crystalline, organic base, obtained from rosaniline by reduction, and also from other sources. It forms colorless salts.</def>

<h1>Leuch\'91mia</h1> <Xpage=845>

<hw>Leu*ch\'91"mi*a</hw> <tt>(?)</tt>, <tt>n.</tt> <ety>[NL., fr. Gr. <?/ white + <?/ blood.]</ety> <fld>(Med.)</fld> <def>See <er>Leucocyth\'91mia</er>.</def> -- <wordforms><wf>Leu*ch\'91m"ic</wf> <tt>(#)</tt>, <tt>a.</tt></wordforms> <altsp>[Written also <asp>leuk\'91mia</asp>, <asp>leuk\'91mic</asp>.]</altsp> <-- now (1990) mainly leukemia -->

<h1>Leucic, Leucinic</h1> <Xpage=845>

<hw><hw>Leu"cic</hw> <tt>(?)</tt>, <hw>Leu*cin"ic</hw> <tt>(?)</tt>,<hw> <tt>a.</tt> <fld>(Chem.)</fld> <def>Pertaining to, or designating, an acid obtained from leucin, and called also <altname>oxycaproic acid</altname>.</def>

<h1>Leucin</h1> <Xpage=845>

<hw>Leu"cin</hw> <tt>(?)</tt>, <tt>n.</tt> <ety>[Gr. <?/ white.]</ety> <fld>(Physiol. Chem.)</fld> <def>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.</def> <-- now called "leucine", one of the essential amino acids (not synthesized by the human body, required component for proper nutrition). <chform>(CH3)2CH.CH2.CH(NH2)-COOH</chform>. L-leucine, the natural form, is present in most proteins. -->

<h1>Leucite</h1> <Xpage=845>

<hw>Leu"cite</hw> <tt>(?)</tt>, <tt>n.</tt> <ety>[Gr.<?/ white: cf. F. <ets>leucite</ets>.]</ety>

<p><b>1.</b> <fld>(Min.)</fld> <def>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.</def>

<p><b>2.</b> <fld>(Bot.)</fld> <def>A leucoplast.</def>

<h1>Leucitic</h1> <Xpage=845>

<hw>Leu*cit"ic</hw> <tt>(?)</tt>, <tt>a.</tt> <fld>(Min.)</fld> <def>Containing leucite; <as>as, <ex>leucitic</ex> rocks</as>.</def>

<h1>Leucitoid</h1> <Xpage=845>

<hw>Leu"ci*toid</hw> <tt>(?)</tt>, <tt>n.</tt> <ety>[<ets>Leucite</ets> + <ets>-oid</ets>.]</ety> <fld>(Crystallog.)</fld> <def>The trapezohedron or tetragonal trisoctahedron; -- so called as being the form of the mineral leucite.</def>

<h1>Leuco-, Leuc-</h1> <Xpage=845>

<hw><hw>Leu"co-</hw> <tt>(?)</tt>, <hw>Leuc-</hw> <tt>(?)</tt>.<hw><ety>[Gr. <?/ white.]</ety> <def>A combining form signifying <i>white</i>, <i>colorless</i>; specif. <fld>(Chem.)</fld>, denoting an extensive series of <i>colorless</i> organic compounds, obtained by reduction from certain other <i>colored</i> compounds; <as>as, <ex>leuc</ex>aniline, <ex>leuc</ex>aurin, etc.</as></def>

<h1>Leucocyte</h1> <Xpage=845>

<hw>Leu"co*cyte</hw> <tt>(?)</tt>, <tt>n.</tt> <ety>[<ets>Leuco-</ets> + Cr. <?/ a hollow vessel.]</ety> <fld>(Physiol.)</fld> <def>A colorless corpuscle, as one of the white blood corpuscles, or those found in lymph, marrow of hone, connective tissue, etc.</def>

<note>&hand; They all consist of more or less spherical masses of protoplasm, without any surrounding membrane or wall, and are capable of motion.</note>

<h1>Leucocyth\'91mia, Leucocythemia</h1> <Xpage=845>

<hw><hw>Leu`co*cy*th\'91"mi*a</hw>, <hw>Leu`co*cy*the"mi*a</hw><hw> <tt>(?)</tt>, <tt>n.</tt> <ety>[NL., fr. Gr. <?/ white + <?/ a hollow vessel + <?/ blood.]</ety> <fld>(Med.)</fld> <def>A disease in which the white corpuscles of the blood are largely increased in number, and there is enlargement of the spleen, or the lymphatic glands; leuch\'91mia.</def>