"from a higher to a lower place, state, or condition," late 12c., from down (adv.) + -ward. As a preposition, "down," by late 14c. As an adjective, "moving or tending from a higher to a lwer place, state, or condition," from 1550s. As an adverb Old English had aduneweard. Downwards (c. 1200), with adverbial genitive, had a parallel in Old English ofduneweardes.

"a downward slope," 1610s, from French déclivité, from Latin declivitatem (nominative declivitas) "a slope, declivity," from declivis "a sloping downward," from de "down" (see de-) + clivus "a slope," from PIE *klei-wo-, suffixed form of root *klei- "to lean."

"in a descending direction," late 14c., from down (adv.) + hill (n.).  From 1590s as a noun, "downward slope of a hill;" meaning "downhill skiing race" is from 1960. As an adjective, "sloping downward, descending," from 1727.

"downward spiraling dive of an aircraft," 1916, from tail (n.1) + spin (n.). Figurative sense of "state of loss of control" is from 1928.

"short, quick, forward and downward motion of the head," voluntary or not, 1530s, from nod (v.).

"to a lower place," Old English adune (adv.), originally a prepositional phrase, of dune "down, downward;" see a- (1) + down (adv.).

1710, "a downward movement," from down (adv.). Football sense of "an attempt to advance the ball" is by 1882.

"set far downward or inward," originally of eyes, late 14c., from deep (adv.) + set (adj.).

also down-grade, "to lower in rank, status, etc.," 1930, from down (adv.) + grade (v.). Related: Downgraded; downgrading. As a noun, "a downward slope," from 1858.

1550s, "cause to turn aside" (transitive), from Latin deflectere "to bend (something) aside or downward," from de "away" (see de-) + flectere "to bend," which is of uncertain origin. The intransitive sense of "to turn away or aside" is from 1610s. Related: Deflected; deflecting.