From WordNet (r) 2.0 (August 2003) [wn]:
mourn
v 1: feel sadness; "She is mourning her dead child"
2: observe the customs of mourning after the death of a loved
one
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Mourn \Mourn\, v. t.
1. To grieve for; to lament; to deplore; to bemoan; to
bewail.
[1913 Webster]
As if he mourned his rival's ill success. --Addison.
[1913 Webster]
And looking over the hills, I mourn
The darling who shall not return. --Emerson.
[1913 Webster]
2. To utter in a mournful manner or voice.
[1913 Webster]
The lovelorn nightingale
Nightly to thee her sad song mourneth well.
--Milton.
[1913 Webster]
Syn: See Deplore.
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Mourn \Mourn\ (m[=o]rn), v. i. [imp. & p. p. Mourned
(m[=o]rnd); p. pr. & vb. n. Mourning.] [AS. murnan; akin to
OS. mornian, OHG. mornen, Goth. ma['u]rnan.]
1. To express or to feel grief or sorrow; to grieve; to be
sorrowful; to lament; to be in a state of grief or
sadness.
[1913 Webster]
Abraham came to mourn for Sarah, and to weep for
her. --Gen. xxiii.
2.
[1913 Webster]
2. To wear the customary garb of a mourner.
[1913 Webster]
We mourn in black; why mourn we not in blood?
--Shak.
[1913 Webster]
Grieve for an hour, perhaps, then mourn a year.
--Pope.
[1913 Webster]