A quick Google search wasn't much of a help, although I did learn about something called a bifurcated divorce (learn more here). Apparently a popular use for this word involves divorce.
I'll assume the definition is a bit different when we are referring to relays. Here is where I saw it on our website, referring to our IDEC RU series of general purpose power relays.
Looking up a few definitions told me that bifurcate means to divide into two parts, to separate into two parts or to fork or divide into two parts.
When referring to relays I finally found a definition on RelayMasters.com (thank you!) - basically it is a contact with two simultaneously operating contact points. Twin (or bifurcated) contacts increase the contact reliability considerably, especially when switching low currents and voltages (dry circuits) and are used for reduction of contact resistance. Bifurcated contacts are twin contacts with the two contact points on one contact member (contact blade).
Bifurcated contacts reduce contact bounce, increase reliability and assist in switching. Bifurcated contacts conduct the switching more efficiently.
In the past, bifurcated relays were costly and generally special order. As they become more popular, especially in the elevator industry, more companies are stocking and reworking the price structure.
Marshall Wolf Automation is your authorized IDEC distributor for their complete line of relays, industrial DC power supplies, photoelectric sensors, LED pilot lights and much more.