descend
v.v. to move from a higher place to a lower one. You use this when you go down stairs, a mountain, or even when a plane lands.
v. to move or fall downwards from a higher position. Intransitive or transitive; often used in formal or literary contexts to describe physical movement or a shift in state.
The hikers began to descend the mountain before sunset.
The flight attendants asked everyone to stay seated as the aircraft began to descend toward the airport.
As the sun began to set, a thick, grey mist started to descend over the valley, obscuring the path and forcing the travelers to halt their journey.
PIE word *de The verb is derived from Middle English descenden (“to move downwards, fall, descend; to slope downwards; to go from a better to a worse condition, decline, degenerate; to be a descendant, derive from (a source); etc.”), from Anglo-Norman descendere, descendre, and Old French descendere, descendre (“to move downwards, fall, descend; to slope downwards; to be a descendant, derive from (a source); etc.”) (modern French descendre), and from their etymon Latin dēscendere, the present active infinitive of dēscendō (“to come or go down, fall, descend; to slope downwards; to be a descendant; etc.”), from de- (prefix meaning ‘from; down from’) + scandō (“to ascend, climb; to clamber”) (from Proto-Indo-European *skend- (“to climb, scale; to dart; to jump”)). The noun is derived from the verb.
Can be used transitively ('descend the stairs') or intransitively ('the elevator descended').
The sun descended downThe sun descendedDescend already means to move down, so adding 'down' is redundant.