WordWeb Online

1. Appear suddenly
   - burst out
    
2. Bulge outward
   - start, protrude, pop, bulge, bulge out, bug out, come out
    
3. Exit briefly
   "He popped out for a quick coffee break"
    
4. Come out suddenly or forcefully
   "you stick a bill in the vending machine and the change pops out"

Derived forms: popping out, pops out, popped out

Type of: appear, change form, change shape, come forth, come out, deform, egress, emerge, exit, get out, go forth, go out, issue, leave

Antonym: pop in