Only with reading も
Archaic noun meaning calamity or misfortune, restricted to the reading も. Not used in modern Japanese outside of historical or literary contexts.
The year-long period of mourning has come to an end.
Because I am in mourning, I will refrain from New Year's greetings.
In classical language, 喪 can be used to mean calamity.
The house next door had a death in the family last month.
葬式 is the funeral ceremony itself, while 喪 is the broader period or condition of mourning that follows it.
忌 and 喪 both mean the period of mourning after a death, but 喪 is the more common everyday word (as in 喪中, 喪服) while 忌 sounds more formal or religious and is also used as a suffix for death anniversaries (一周忌).
藻 (seaweed/algae) is pronounced identically to 喪 (mourning) but has a completely unrelated meaning, so context alone distinguishes them.
Standard kanji spelling for mourning and bereavement contexts.
The kanji 喪 originally depicted a person mourning with a mulberry tree, symbolizing loss. The reading も is the native Japanese term for mourning, while そう is the Sino-Japanese reading used in compounds.