In Shakespeare's time, what were the audience members who stood closest to the stage during a performance called?

When plays took place at the Elizabethan theatre, those people who stood near the stage in the central inner area were called the groundlings. 

The groundlings were all those people in attendance who were not well-to-do as the wealthier people sat in covered galleries around the stage. These ground spectators stood in the yard around the platform stage which was without a front curtain, making the exits and entrances of the actors visible to all. Action and excitement was demanded by the audiences, but they also loved the music of good language. They responded to the beauty and grandeur of verse spoken by the main characters, as well as the puns and word games. Of course, they also delighted in physical comedy.

Shakespeare often began his plays with an initial scene in which there was vigorous action that would grab the groundlings' attention. Boisterous humor was also often used to hold the attention of these people.
The opening scene of Romeo and Juliet, for instance, fulfills both the demand for action and ribald humor as the servants of the House of Capulet make several puns on the words collier, choler, and collar--

Gregory. No, for then we should be colliers [coal-dealers].
Sampson. I mean, an [if] we be in choler [anger], we'll draw---

before they quarrel with the servants of the Montagues and then engage in an exciting sword fight.