Accidental: Many users have lost their data due to accidental deletion.
happening or existing by chance:
assemble:The assembler wears a harness that is attached to suspended ropes.
to come together in a single place or bring parts together in a single group.
calculate: Measure your head to calculate the size of your crown.
to judge the number or amount of something by using the information that you already have, and adding, taking away, multiplying, or dividing numbers: