(Lac*ton"ic), a. [From Lactose.] (Chem.) Pertaining to, or designating, an acid obtained by
the oxidation of milk sugar
(Lac`to*pro"te*in) n. [L. lac, lactis, milk + E. protein.] (Physiol. Chem.) A peculiar albuminous
body considered a normal constituent of milk.
(Lac"to*ry) a. Lactiferous. [Obs.] "Lactory or milky plants." Sir T. Browne.
(Lac"to*scope) n. [L. lac, lactis + scope.] An instrument for estimating the amount of
cream contained in milk by ascertaining its relative opacity.
1. (Physiol. Chem.) Sugar of milk or milk sugar; a crystalline sugar present in milk, and separable from
the whey by evaporation and crystallization. It has a slightly sweet taste, is dextrorotary, and is much
less soluble in water than either cane sugar or glucose. Formerly called lactin.
2. (Chem.) See Galactose.
(||Lac*tu"ca) n. [L., lettuce. See Lettuce.] (Bot.) A genus of composite herbs, several of which
are cultivated for salad; lettuce.
(||Lac`tu*ca"ri*um) n. [NL., fr. L. lactuca lettuce.] The inspissated juice of the common
lettuce, sometimes used as a substitute for opium.
(Lac*tu"cic) a. (Chem.) Pertaining to, or derived from, the juice of the Lactuca virosa; said
of certain acids.
(Lac*tu"cin) n. [From Lactuca: cf. F. lactucine.] (Chem.) A white, crystalline substance,
having a bitter taste and a neutral reaction, and forming one of the essential ingredients of lactucarium.
(Lac*tu"cone) n. [From Lactuca.] (Chem.) A white, crystalline, tasteless substance, found
in the milky sap of species of Lactuca, and constituting an essential ingredient of lactucarium.
(Lac`tu*ram"ic) a. [Lactic + urea + amic.] (Chem.) Pertaining to, or designating, an organic
amido acid, which is regarded as a derivative of lactic acid and urea.
(Lac"tyl) n. [Lactic + - yl.] (Chem.) An organic residue or radical derived from lactic acid.
(||La*cu"na) n.; pl. L. Lacunæ (#); E. Lacunas [L., ditch, pit, lake, orig., anything hollow. See
1. A small opening; a small pit or depression; a small blank space; a gap or vacancy; a hiatus.
2. (Biol.) A small opening; a small depression or cavity; a space, as a vacant space between the cells of
plants, or one of the spaces left among the tissues of the lower animals, which serve in place of vessels
for the circulation of the body fluids, or the cavity or sac, usually of very small size, in a mucous membrane.
(La*cu"nar) a. Pertaining to, or having, lacunæ; as, a lacunar circulation.
(La*cu"nar), n.; pl. E. Lacunars L. Lacunaria [L.] (Arch.) (a) The ceiling or under surface
of any part, especially when it consists of compartments, sunk or hollowed without spaces or bands
between the panels. Gwilt (b) One of the sunken panels in such a ceiling.
(La*cune") n. [F.] A lacuna. [R.] Landor.