Later and Postmortem

Later adjective - Being, occurring, or carried out at a time after something else.

Postmortem and later are semantically related In some cases you can replace term "Postmortem" with "Later", this adjectives are similar.

Postmortem adjective - Occurring after one's death.

Later and postmortem are semantically related in following death topic. Sometimes you can use "Later" instead an adjective "Postmortem".