doorbell
noun
1. a push button at an outer door that gives a ringing or buzzing signal when pushed
verb
1. (intransitive) To ring many doorbells in an effort to contact people and thereby spread information or solicit.
2. (transitive) To ring many doorbells of (target people or an area) in an effort to contact people and thereby spread information or solicit.
- We doorbelled the whole district in an effort to get out the vote.