An old fashioned term
If you look in any old beekeeping book you will see reference to "pulled virgins", but if you put it into a search engine you won't get much to do with bees! It is a term that is very rarely used in modern beekeeping.
The term is used for any virgin queen that is released from her cell into a colony by the beekeeper, hence "pulled", "pull" or "pulling". An example is when perhaps there have been virgins emerge and it is not known if the colony has swarmed or not. Perhaps the fertile queen has already gone with a swarm several days earlier, she was clipped and didn't get back or had been removed by the beekeeper some days before. In cases like this several queens sometimes emerge when you are inspecting a colony, suggesting the bees are preventing emergence, perhaps by crowding around the end of the queen cell. This could be because the colony is waiting for the weather to improve or for later in the day before swarming. When you open the colony the bees disperse and the queens emerge, sometimes so fast it is difficult to catch them.
If you see a virgin queen and you don't need any more queens you can safely remove all the queen cells. If you don't see any virgin queens, to remove all queen cells might leave the colony hopelessly queenless if a swarm has just gone with all the emerged virgins.
By "pulling" one or more virgin queens you will be certain the colony will have a queen. If you remove all other queen cells you will make sure the colony won't swarm, even if there are half a dozen virgin queens running around. This relies on the almost certainty that if there are no queen cells left the colony won't swarm. If there is more than one virgin queen they will fight.