mourn

Short definition from Wiktionary

Verb

1. 1
   To express sadness or sorrow for; to grieve over (especially a death).
2. 2
   To utter in a sorrowful manner.
3. 3
   To wear mourning.

Noun

1. 1
   Sorrow, grief.
2. 2
   A ring fitted upon the head of a lance to prevent wounding an adversary in tilting.