mid-15c., "to strike so as to cause to make a short, quick sound;" intransitive sense "make a short, quick sound" is from 1570s; imitative. Of eyes, "to protrude" (as if about to burst), from 1670s. Sense of "to appear or to put with a quick, sudden motion" (often with up, off, in, etc.) is recorded from mid-15c. Baseball sense of "to hit a ball high in the air" is from 1867. To pop the question is from 1725, specific sense of "propose marriage" is from 1826. Related: Popped; popping.
<a href="https://www.etymonline.com/word/popper">Etymology of popper by etymonline</a>
Harper, D. (n.d.). Etymology of popper. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/popper