abandon, throw away, discard, resign, reject, sacrifice
棄 centers on letting go of something completely: abandoning, discarding, or throwing away. The ideas of resigning, rejecting, and sacrificing are natural extensions of giving something up.
棄 is thought to depict a child being abandoned in a basket, with the top representing a container and the bottom 木 suggesting a wooden structure. The modern form retains this general idea, though the exact historical components are not fully clear.
Imagine a wooden basket (木) with a lid (亠) and something inside (厶,凵) being thrown away. The whole scene shows discarding an unwanted item.
For キ, picture a key being thrown away into a basket: key -> キ, and you abandon the key as you discard the basket.
abandonment; renouncement; renunciation; resignation; abdication; surrender; relinquishing; waiving; giving up
disposal; abandonment; scrapping; discarding; abolition
tearing up and discarding (e.g. documents); destruction
desperation; despair; self-abandonment
abstention (from voting); renunciation (of a right); withdrawal (from a contest)
abandonment; desertion
abandonment; giving up; throwing away; disposal; dumping
rejection; dismissal; turning down; abandoning; renunciation
desperation; despair; self-abandonment
apostasy; renunciation (e.g. of a religion); defection
abandoned people (people left to fend for themselves after a war or natural disaster)
disdain; contempt; scorn; abhorrence
cell discarding
cell loss rate
frame discard
domestic waste; general waste; non-industrial waste
illegal dumping; fly-tipping
low-level radioactive waste
debt forgiveness; debt waiver
hospital waste