Obsolete/obsolescent

When something is obsolete, it’s out-of-date or out of use; if it’s obsolescent, it’s in the process of becoming out-of-date or out of use. So what is obsolescent today may well be obsolete tomorrow.
Hopefully, these obsolescent words will never become obsolete.
Guilt/shame

When you do something bad, should you feel guilt? Or should you feel shame? According to this study of psychological terms that people often get wrong, shame is a global negative evaluation of the self in the wake of a behaviour,” whereas “guilt is a specific negative evaluation of the behaviour, itself.” (As in, “I did a bad thing.”) Therefore, as Pepperdine University Professor Steven Sultanoff, PhD puts it, with shame, you think, “I did something bad, which makes me a bad person,” but with guilt, you think, “I did something bad, but I’m still a good person.”
Amicable/amiable

“Amicable” refers to a friendliness or goodwill between people or groups. “Amiable” refers to one person’s friendly disposition. A group might have an amicable meeting, because the people there are amiable.