1. hap
2. go on, pass off, occur, pass, fall out, come about, take place, befall
3. bechance, hap, go on, pass off, occur, pass, fall out, come about, take place, chance
4. materialize
5. materialise, hap, go on, pass off, occur, pass, fall out, come about, take place, find
5. chance, bump, encounter