(geology) A geologic marker created by a global event that leads to long lasting global changes recorded in the geologic record that can be used to indicate a change in a geologic time division such as an epoch, age, era.

(music) Any of a number of stringed instruments in which the handle passes diametrically through the resonator and which are played with a bow.

(chemistry) A calibration technique for quantification that involves adding known amounts of a substance to an aliquot of an analyte.

plural of spike oil

oil of spike

Luzula spicata, a flowering plant in the family Juncaceae.

(transitive) to cause to become spiky / (intransitive) to become spiky / (intransitive) to increase sharply

(historical, weaponry) A small blade or spike on the rear end of a spear, used as a counter-balance and as backup if the spear broke.

(US) Three horses, or a horse and a yoke of oxen, harnessed together, a horse leading the oxen or the span.

plural of spike protein