unfrequent
/ʌnˈfrɛkənt/Definitions
1. adjective
not occurring or happening often; infrequent
“She often complains about the unfrequent public transport in this area.”
2. noun
a person or thing that is not frequent; an infrequent person or thing
“The manager told us that many of our customers are unfrequents who only visit once a year.”