The term secular is used to distinguish non-religious things from religious ones. The thing need not be anti-religious to be secular; in fact, that would likely be a misleading use of the term. Instead, describing something as secular generally means it is not religiously oriented.
For example, the United States government is, under the Constitution, a secular government. That does not mean the government acts against the interests of religion, nor does it mean that the people who make up the government must be non-religious. On the contrary, it means that the government must remain neutral with respect to religion, to the extent possible.
At a secular event, one is expected to "leave religion at the door". One is not asked to change their beliefs, but rather to restrain themselves from attempting to inculcate others into their beliefs.
Secular does not imply atheistic.