I'm no expert but I think it has "meaning" in several contexts. 1) Sung to celebrate/commemorate the repose of a known Saint within a formal service. 2) Spoken and sung in memory of faithful laity who have reposed. Our "mother" church (We attend a small mission 45 min. away) has a monthly service for the departed for those who have reposed through the years in that particular month. 3) Sung for the recently departed as a pray that they will be in the presence of God, as in being received and "remembered/allowed" to remain in His presence eternally. 4) May be spoken to grieving family and friends of the departed as a condolence/prayer to mean the same as #3.
These are my musings and observations and may not be specifically correct.