上述單詞具有共犯或從犯的含義。其中，accomplice和confederate 的含義相近， 在美國，其有雙重含義：一是“共犯”， 指與他人一起共同實(shí)施犯罪，不論其身份是主犯或從犯[1 ] ；二是“從犯”[2]，此時(shí)其主要指在策劃或?qū)嵤╇A段，協(xié)助他人犯罪 或故意不履行法定阻止義務(wù)而旨在加速或促進(jìn)犯罪的實(shí)施者， 因此，一個(gè)accomplice或confederate可能但不必一定親自作案[3]，此時(shí)其等同accessory。abettor則指直接參與犯罪者，故其應(yīng)為“共犯”[4]，如：A look-out is an abettor in a bank robbery (銀行搶劫案中的放哨者是該案的共犯）:abettor也可拼寫為abetter，其也稱為 principal in the second degree (二級(jí)主犯）。相比之下，accessory則為“從犯”，與主犯（principal)相對，主要指協(xié)助重罪犯犯罪者。它分為兩類，如果此種協(xié)助是在犯罪預(yù)備時(shí)進(jìn)行，被稱為an accessory before the fact (事前從犯）;如果是在罪犯之后協(xié)助罪犯脫逃，也被稱為an accessory after the fact (事后從犯）[5](有關(guān)此種分類現(xiàn)在的區(qū)別，參見條目accessory before the fact) 。
 
[1 ]“ A person who is in any way concerned with another in the commission of a crime，whether as principal in the firet or second degree or as a accessory. " Cf. Bryan A. Gamer, Black's Law Dictionary, 7th edition, at p. 16，West Group (1999).
[2 ]“A person knowingly, voluntarily, and intentionally unites with the principal offender in committing a crime and thereby becomes punishable for it. ” Id. at p. 16.
[3 ]“Person is liable as an accomplice to the crime of another if he gave assistance or encouragement or failed to perform a legal duty to prevent it with the intent thereby to promote or facilitate commission of the crime. ” Cf. The Publisher's Staff, Black's Law Dictionary, abridged 6th edition, at p. 10, West Publishing Co. (1997).
[4 ]“An abettor is an accomplice or confederate who is present and who participates in the execution of a crime. ” Cf. The Editors of the Reader’s Digest, Use the Right Word, at. p. 3, The Reader's Digest Association Proprietary Ltd. (1971 ).
[5 ]“A person who is not actually or constructively present but with criminal intent contributes as an assistant or instigator to the commission of a felony, also called accessory before the fact ”、" A person who knowing that a felony has been committed aids，assists, or shelters the offender with the intent to defeat justice，also called accessory after the fact." Cf. Linda Picard Wood，J. D.，Merriam Websters Dictionary of Law，at p. 6, Meniam-Webster, Incorporated, Springfield, Massachusetts (1996).