posthumous name
諡 centers on a name given after death to honor a person's life, a posthumous name. It is a specific historical and ceremonial concept with no broader abstract extensions.
諡 combines 言 (words, speech) with 㿽, a component that likely contributes sound and relates to increase or benefit, suggesting a name that adds honor after death. The exact historical development of the right side is uncertain.
Words 言 on the left and a vessel-like shape 㿽 on the right: imagine a ceremonial vessel inscribed with words to honor the deceased, creating their posthumous name.
For エキ, picture a liquid (liquid -> エキ, from 液) being poured from a vessel as part of the naming ceremony, the sound of the pouring echoing the reading.