Switch
From wipipedia.org
In BDSM, a switch is someone who participates in BDSM activities as both a top and a bottom. A switch will be the top on some occasions and the bottom on other occasions. Switches are very common; partners may switch roles based on mood, desire, or being with a different partner.
A 'switch' may be in a relationship with someone of the same primary BDSM orientation (two dominants, say), so switching provides each partner with an opportunity to realize his or her unsatisfied BDSM needs with others.
A person who engages in self-bondage can be viewed as taking both roles simultaneously.
See also
Bigoted or insecure people can have problems with switches which stems from the fear of that which is not easily labelled or indentified.
