I guess I should start this by noting, for those of you who have not been in this crack on the surface of the internet long, that I am an Atheist. My username is actually a portmanteau of heretic and infidel, both of which are synonyms for Atheist, so I could be (Atheist)(Atheist)=Atheist2. .
Not really on the main topic, but I question your idea of "synonyms for Atheist".
a⋅the⋅ist /ˈeɪθiɪst/ [ey-thee-ist]
–noun
a person who denies or disbelieves the existence of a supreme being or beings.
her⋅e⋅tic /n. ˈhɛrɪtɪk; adj. ˈhɛrɪtɪk, həˈrɛtɪk/ [n. her-i-tik; adj. her-i-tik, huh-ret-ik]
–noun
1. a professed believer who maintains religious opinions contrary to those accepted by his or her church or rejects doctrines prescribed by that church.
2. Roman Catholic Church. a baptized Roman Catholic who willfully and persistently rejects any article of faith.
3. anyone who does not conform to an established attitude, doctrine, or principle.
–adjective
4. heretical.
in⋅fi⋅del /ˈɪnfɪdl, -ˌdɛl/ [in-fi-dl, -del]
–noun
1. Religion.
a. a person who does not accept a particular faith, esp. Christianity.
b. (in Christian use) an unbeliever, esp. a Muslim.
c. (in Muslim use) a person who does not accept the Islamic faith; kaffir.
2. a person who has no religious faith; unbeliever.
3. (loosely) a person who disbelieves or doubts a particular theory, belief, creed, etc.; skeptic.
–adjective
4. not accepting a particular faith, esp. Christianity or Islam; heathen.
5. without religious faith.
6. due to or manifesting unbelief: infidel ideas.
7. rejecting the Christian religion while accepting no other; not believing in the Bible or any Christian divine revelation.
8. Also, in⋅fi⋅del⋅ic /ˌɪnfɪˈdɛlɪk/ [in-fi-del-ik] . of, pertaining to, or characteristic of unbelievers or infidels.
So
one definition of "heretic" or "infidel" can be
loosely interpreted as synonymous with "atheist" but each word has other connotations that have little-or-nothing to do with disbelief in gods.