The December solstices mark the longest and shortest days of the year.

The Decade Volcanoes are a group of sixteen volcanoes identified by the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI) as being worthy of particular study in light of their history of large, destructive eruptions and proximity to populated areas.

The decay chains of radioactive elements can be complex.

The military conducted several decapitation strikes on enemy leaders.

The military launched a decapitation strike against the enemy leadership.

They have a May-to-December relationship.

They have a May-December relationship.

She is a December bride.

The dentist explained that the decay in my tooth was caused by a lack of proper oral hygiene.

Tooth decay is a common dental problem.