Seguidilla, seg-i-dēl′yä, n. a lively Spanish dance for two: music for such a dance.

Seiche, sāsh, n. a remarkable fluctuation of the level observed on the Lake of Geneva and other Swiss lakes, probably due to local variations in the barometric pressure. [Fr.]

Seidlitz, sēd′litz, adj. saline water of or from Seidlitz in northern Bohemia, also a saline aperient powder.

Seignior, Seigneur, sē′nyor, n. a title of honour and address in Europe to elders or superiors: the lord of a manor.—ns. Seign′iorage, Seign′orage, a royalty: a share of profit: a percentage on minted bullion; Seignioral′ty, the authority or the territory of a seignior or lord.—adjs. Seigniorial (sē-nyō′ri-al), Seigneu′rial, Signō′rial, manorial.—v.t. Seign′iorise, to lord it over.—ns. Seign′iory, Seign′ory, the power or authority of a seignior or lord: a domain, a lordship without a manor, or that of manor whose lands were held by free tenants: the elders forming the municipal council in a medieval Italian republic.—Grand Seignior, the Sultan of Turkey. [Fr. seigneur—L. seniorsenex, old. In Late. L. senior is sometimes equivalent to dominus, lord.]

Seil, sīl, v.t. (Scot.) to strain.—n. a strainer. [Sile.]

Seine, sān, or sēn, n. a large net for catching fish.—v.t. to catch with such.—ns. Seine′-boat; Seine′-en′gine, a steam-engine used in hauling seines; Seine′-gang, a body of men engaged in seining, with their boats and other gear; Sein′er, one who seines: a vessel engaged in purse-seining for mackerel; Sein′ing, the art of using the seine. [Fr.,—L. sagena—Gr. sagēnē, a fishing-net.]

Seirospore, sī′rō-spōr, n. one of the non-sexual spores arranged in a chain in certain florideous algæ.—adj. Seirospor′ic.

Seised, sēzd, adj. (Spens.) taken possession of.—n. Seis′in (Spens.), possession.

Seismograph, sīs′mō-graf, n. an instrument for registering the shocks and concussions of earthquakes, a seismometer.—adjs. Seis′mal; Seis′mic, belonging to an earthquake.—ns. Seis′mogram, the record made by a seismometer; Seismog′rapher.—adjs. Seismograph′ic, -al, connected with the seismograph.—n. Seismog′raphy, the study of earthquake phenomena.—adjs. Seismolog′ic, -al.—ns. Seismol′ogist, a student of earthquake phenomena; Seis′mologue, a catalogue of earthquake observations; Seismol′ogy, the science of earthquakes and volcanoes; Seismom′eter, an instrument for measuring shakings, tremors, and tiltings of the earth.—adjs. Seismom′etric, -al.—ns. Seismom′etry, the measuring the phenomena of earthquakes; Seis′moscope, a name of the simpler form of seismometer.—adj. Seismoscop′ic. [Gr. seismos, an earthquake, graphein, to write.]

Seison, sī′son, n. a genus of parasitic leech-like rotifers.