The full quotation is "What's in a name? That which we call a rose by any other word would smell as sweet."
Juliet says this in the Balcony Scene of Romeo and Juliet. What she is getting at is that even if you called a rose a scranjedip, it would still look and smell just as pretty. What you call things doesn't change what they are--it's just another name for the same thing.
The reason she is pondering this is made clear in the next line "So Romeo would, were he not Romeo called, retain that dear perfection which he owes without that title." Unscrambled a little, this comes out as "If Romeo were not called Romeo, he would still retain that dear perfection he owns without that name." Juliet is working through the problem that she loves Romeo but has been told that all the Montagues are her enemy. She says that if Romeo were called Bob Smith, he'd still be just as perfect, the same way as the rose would smell sweet even if you called it a scranjedip.