(chemistry) a vertical series of elements in the periodic table that have three valence electrons; boron is a metalloid, while aluminium, gallium, indium and thallium are metals

(chemistry) the vertical group of the periodic table containing carbon, silicon, germanium, tin and lead; the elements have a valence of 4, and show the typical gradation from nonmetal to metal

Innovative; new, different; doing something that has never been done before.

The point at which construction begins, by digging into the ground. / A ceremony to mark the beginning of construction.

Lagopus lagopus, a medium-sized bird in the grouse family.

(chiefly in the plural) Hulled grain, chiefly hulled oats.

(archaic or historical) Any of various old coins of England and Scotland. / A historical English silver coin worth four English pennies, still minted as one of the set of Maundy coins.

A group of people, sampled from a larger population, interviewed in open session for market research or political analysis.

A red-brown marmot, Marmota monax, native to North America. / (rare) The aardvark.

(mathematics) A group of isometries leaving a fixed point.