In Act 4, Scene 2, Quince mistakes the word paragon for paramour. Quince is trying to say that no one in the company speaks as well as Bottom but instead says complete nonsense. The word paragon means "model" while a paramour is a lover, especially an "adulterous lover." We see Quince mistake the word paragon for paramour in his lines, "Yea, and the best person too; and he is a very paramour for a sweet voice" (IV.ii.11-12). Flute corrects his mistake by saying, "You must say 'paragon.' A paramour is--God bless us!--A thing of naught," meaning complete nonsense (13-14).
However, while it is completely nonsensical for Quince to say that Bottom is an adulterous lover when it comes to his voice, we can see some reason and meaning behind Shakespeare's choice of word. Since a paramour is also a lover, Quince can be saying that Bottom is a lover of a sweet voice, meaning that Bottom loves a sweet voice. One thing we see about Bottom is that he sincerely loves theatrical arts. He is very enthusiastic about performing a play, so enthusiastic that he tries to take on other cast members' roles in the play as well. He tries to take on the role of Thisbe, the lead female role, even though he is already playing Pyramus, the lead male role. He also tries to take on the role of the lion. He is so enthusiastic about envisioning himself in roles and taking them on that he has to be reminded that he "can play no part but Pyramus" (I.ii.76). Since Bottom is so enthusiastic about acting and seeing acting performed well, we can indeed say that Bottom is a lover of a "sweet voice," meaning that he loves hearing lines spoken well. Hence, we can see that while Quince's word mix-up is nonsensical, the word "paramour" also helps to characterize Bottom.