propulse

As a verb propulse

is (obsolete|transitive) to repel; to drive off or away.

As a noun null is

zero, nil; the cardinal number before einn.

As verbs the difference between propel and propulse

is that propel is to cause to move in a certain direction while propulse is to repel; to drive off or away.

As a noun prepulse

is a weak pulse (stimulus) that inhibits a reaction to a subsequent stronger one.

As a verb propulse is

(obsolete|transitive) to repel; to drive off or away.