nonrespondent
noun
non·re·spon·dent
| \ ˌnän-ri-ˈspän-dənt
\
\
plural nonrespondents
Definition of nonrespondent
: someone who is not a respondent
especially
: someone who does not respond to a poll
Many nonrespondents said that they did not feel knowledgeable enough about fishing to answer the questionnaire. — Chuck Harris and Eric Bergersen