Some dictionaries include the term "moral" and some don't. And In some cases it depends on which definition one wants to choose.
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Encarta® World English Dictionary, North American Edition
http://encarta.msn.com/dictionary_1861735025/sin.html
1. transgression of theological principles: an act, thought, or way of behaving that goes against the law or teachings of a religion, especially when the person who commits it is aware of this
2. shameful offense: something that offends a moral or ethical principle
3. estrangement from God: in Christian theology, the condition of being denied God's grace because of a sin or sins committed.
intransitive verb (past and past participle sinned, present participle sin·ning, 3rd person present singular sins)
Definition:
1. knowingly do wrong: to commit a sin, especially by knowingly violating the law or teachings of a religion
2. commit shameful offense: to commit a serious moral or ethical offense.
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Compact Oxford English Dictionary
http://www.askoxford.com/concise_oed/sin_1?view=uk
• noun
1 an immoral act considered to violate divine law.
2 an act regarded as a serious offence.
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Merriam-Webster's Online Dictionary
http://www.m-w.com/cgi-bin/dictionary?b ... ary&va=sin
1 a : an offense against religious or moral law b : an action that is or is felt to be highly reprehensible <it's a sin to waste food> c : an often serious shortcoming : FAULT
2 a : transgression of the law of God b : a vitiated state of human nature in which the self is estranged from God
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Cambridge Dictionary of American English
http://dictionary.cambridge.org/define. ... 1+0&dict=A
an act of breaking a religious law, or such acts considered together.
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1. transgression of theological principles: an act, thought, or way of behaving that goes against the law or teachings of a religion, especially when the person who commits it is aware of this.
1. knowingly do wrong: to commit a sin, especially by knowingly violating the law or teachings of a religion
1 an immoral act considered to violate divine law.
1 a : an offense against religious or moral law.
An act of breaking a religious law, or such acts considered together.
The word "moral" isn't an absolute necessity or concept in defining sin in many dictionaries. Nor is "moral knowledge" or "moral judgment" required to define sin. In fact, the use of the term "moral" or "morality" is used in only about 50% of the definitions in the #1 or predominate positions of most dictionaries.
I seroiusly believe "moral knowledge" and "moral judgment" can not be applied to define the sin of Adam. These phrases act only to add to sin's definition for the purpose of supporting the views of those who use them. It would appear then that "morality" is born through or a product of the knowledge of good and evil.