1
general::
noun sadness about sb's death ADJ. deep | national, official VERB + MOURNING be in, go into He was in deep mourning for his dead wife. MOURNING + NOUN clothes PHRASES a day/period of mourning a day of mourning for the victims of the tragedy | a state of mourning clothes ADJ. full VERB + MOURNING wear PREP. in ~ She was still in full mourning six months after her son's death.
Oxford Collocations Dictionary