simple past tense and past participle of activate

Synonym of class action

plural of class action lawsuit

(chemistry, physics) The energy required to initiate a reaction. For example, the flame from the fuse of a firecracker provides a small initial amount of energy, after which the explosive reaction proceeds by itself, releasing a considerably larger quantity of energy. A small push given to a stable but top-heavy object may cause it to fall over; the potential energy released during the fall was present in the system all along but could not be realized as long as the object was upright and balanced.

(volcanology, geology) A volcano that has erupted in the last 10,000 years, although not necessarily venting lava or gases now.

In set dances with more than one couple dancing, the couple doing the more complicated movement during any given portion of the dance. The role of active couple may pass from one couple to another. In many quadrilles, certain figures will have two active couples at any one time; in long set dances, quite often every other couple or every third couple is the active couple.

(biochemistry, uncountable) A globular structural protein that polymerizes in a helical fashion to form an actin filament (or microfilament). / (biochemistry, countable) One of the six isoforms of actin.

plural of course of action

A plan; a set of intended actions, through which one intends to achieve a goal.

Speaking, promising, or boasting much, but doing little.