I believe that the title is ironic and metaphorical. The rose, as has been pointed out, is directly related to romance and marriage in the text. The rose represents the idea of marriage for Miss Emily and so we might read the title as "A Marriage for Miss Emily". The marriage is ironic, obviously, as the groom is a dead man. Emily killed him with poison.
Roses are used in commemoriation of events and accomplishments -- think of the Kentucky Derby winning horse. This story could be considered a rose in that the narrator, while wanting to tell us a great story about the crazy lady who killed a man and left him in her upper rooms for years, also tells us of some the details about her life that create sympathy for a lady who never really had what she wanted from life. She has crazy relatives, a father who sent away all her suitors, and a "boy friend" who is "not the marrying kind." While we don't applaud her actions, we come to understand them. In a way, this story honors Emily, just like all of the townspoeple come out for her funeral, some out of curiosity and some from a sense of duty and respect for "the fallen monument" that is Miss Emily.
The rose in the title can be interpreted several ways. The rose is most often thought of as a symbol for love in which case Homer is the "rose" or love for Emily. Her father thought no man was good enough for her or for the Grierson family. Therefore she was never able to experience passion or the rose of love until she met Homer. However, there is another meaning of rose to consider. In Medieval times the rose was used as a sign of silence or secrecy. A rose was hung from the ceiling at a meeting of secret societies indicating a demand for discretion. The rose in the title of the story could therefore stand for Emily's secret; that is Homer her "rose" whom she cherished, loved and kept to herself even after his body was corrupted by the decay of time.
The title of "A Rose for Emily" refers to the traditional flower given to represent romantic love. Emily never got that love, and never really got given those symbols that would indicate it. That's part of what soured her on life and love, and made her want to seize a loved one…even if it meant killing him.You can see references to "rose" in the final section—large portions of the sick bedroom are rose-colored. Faulker also uses the verb "rose" other places in the story: the dust rose, and the townspeople rose. I don't think this is an accident. The first shows her passing; the second shows the respect she is given instead of love.
Emily... wAs cOmpAreD tO e rOsE 4 HeR dEaTh..♥♥
Flowers are given usually given to celebrate occasions. In this case the occasion celebrated is death.
Everything in life dies and eventually the rose will die and unite with Emily.