棄 discard

I got drunk and discarded my house-KEY. Now my wife makes me sleep in the yard.

If you can deal with the fact that the brush radical is tilted sideways, then have I got a mnemonic for you!

I killed the cow with a fork, and discarded the decapitated cow-head in a tree. No one will think to look for it there!

resign ★☆☆☆☆
放 (release) + 棄 (discard) = 放棄 (resign)

renounce, resign, "I don't sell that shit no more, dude."

annul ☆☆☆☆☆ NP
廃 (wane) + 棄 (discard) = 廃棄 (annul)

dispose of - usually used of specialized garbage: medical waste or nuclear boogers or whatever.