If abortion = homicide, is abortion justified?

If some homicides = justifiable, then can abortion = justifiable homicide?

http://dictionary.reference.com/search?q=homicide

hom·i·cide n. 1. The killing of one person by another. 2. A person who kills another person.

[Middle English, from Old French, from Latin homicdium, and homicda hom, man]

Source: The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2000 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

homicide n. [F., fr. L. homicidium, fr. homicida a man slayer; homo man + caedere to cut, kill.] The killing of one human being by another.

Note: Homicide is of three kinds: justifiable, as when the killing is performed in the exercise of a right or performance of a duty; excusable, as when done, although not as duty or right, yet without culpable or criminal intent; and felonious, or involving what the law terms malice; the latter may be either manslaughter or murder. --Bouvier.

Proof that a zygote can be regarded to be an aggressor.

Premise: Aggression = Injury.
Premise: Injury = Causing an actual loss or a threat of a loss of life/limb/liberty/property
Conclusion: Aggression = Causing an actual loss or a threat of a loss of life/limb/liberty/property

Premise: Pregnancy/childbirth = Significant risk/threat of a loss of life/limb/liberty/property to a pregnant woman.
Verified: (A) World Health Organization (WHO): Statistics suggest that from 500,000 to 700,000 women per day worldwide die from complications of pregnancy/childbirth, 1369 to 1918 women per day, and the detriments to women's health are not included in these statistics but are certain to add many more to the estimated 500,000 to 700,000 women who die each day from complications of pregnancy and childbirth. (B) The death rate for childbirth = 14/100,000, the death rate for first trimester abortions = 2/100,000 and the death rate for second trimester abortions = 3/100,000, showing ratios of risk of childbirth to be 7 times  the risk of first trimester abortions and 4.3 times the risk of second trimester abortions, thus, abortion is between 4.3 and 7 times safer than childbirth.
Premise: Human zygotes are proof of a de facto pregnancy/impending childbirth.
Conclusion: Human zygotes cause a significant risk/threat of a loss of life/limb/liberty/property to a pregnant woman.

Premise: Aggression = Injury = Causing an actual loss or a threat of a loss of life/limb/liberty/property.
Premise: Human zygotes cause a significant risk/threat of a loss of life/limb/liberty/property to a pregnant woman.
Conclusion: Human zygotes are aggressors whose aggression causes a significant risk/threat of a loss of life/limb/liberty/property to a pregnant woman.

Thus, by the mere fact of causing a significant risk/threat of a loss of life/limb/liberty/property to a pregnant woman, a human zygote is an aggressor.

Now, a pregnant woman can accept the risks and therefore not regard the human zygote to be an aggressor, but that is her choice, and no one else's.

Note that in some cases wherein a criminal attacks a victim, and injures the victim, the victim can 'forgive' the criminal his criminal action/attack, and the law cannot prosecute the criminal without the consent of the victim. This sets the precedent by which a pregnant woman can 'forgive' the human zygote that threatens to kill her/maim her/take away her liberty/rob her of her property [as in the $$ needed for the zygote's medical needs during pregnancy, the cost of childbirth and raising the born child].

Note that in a criminal attack the only person entitled to forgive a criminal is the victim; a rescuer or a witness has no right to forgive a criminal his attack and
injury.

Note that in the definitions of homicide, homicide = the killing of one human being by another human being.

But note also that there are justifications for homicide, the so-called justifiable homicides, which include self-defense and the defense of others.

If abortion = the killing of a human being = homicide, and if because by its mere existence, its presence inside a woman's body, an human zygote threatens a woman's health/life and therefore causes a threat of an actual loss of the woman's life/limbliberty/property, then a woman is justified in defending herself and those who love her and who depend upon her by terminating an unwanted pregnancy, and any homicide involved is justified, therefore, abortion is justifiable homicide.

Premise: Homicide = The killing of a human being by another human being.
Premise: In an abortion, a human being is killed by another human being.
Conclusion: Abortion = Homicide.

Premise: Justifiable homicides are homicides justified as necessary for the defense of oneself or the defense of others from threats of a loss of health/life, a loss of life/limb/liberty/property.
Premise: An abortion = homicide and removes from a woman a threat of a loss of health/life, a loss of life/limb/liberty/property.
Conclusion: Abortion = Justifiable Homicide.