A vent or fissure on the surface of a planet (usually in a mountainous form) with a magma chamber attached to the mantle of a planet or moon, periodically erupting forth lava and volcanic gases onto the surface.

to erupt; to burst forth

Done, given, or acting of one's own free will. / Done by design or intention; intentional. / Working or done without payment. / Endowed with the power of willing. / Of or relating to voluntarism.

(obsolete) Voluntarily.

(music) A short piece of music, often having improvisation, played on a solo instrument. / A volunteer. / A supporter of voluntarism; a voluntarist.

An instrument for measuring electric potential in volts.

(sports) A stroke, in ball sports, in which the ball is hit immediately after it bounces off the ground / (cricket) A delivery that bounces just short of the blockhole

The simultaneous firing of a number of missiles or bullets; the projectiles so fired. / A burst or emission of many things at once. / (sports) The flight of a ball just before it bounces.

(transitive) To fire a volley of shots / (sports, transitive) To hit the ball before it touches the ground / (intransitive) To be fired in a volley / (sports, intransitive) To make a volley

(anatomy) Pertaining to the palm of the hand or the sole of the foot.