First-class and Infrequent

First-class adjective - Of the very best kind.

Infrequent and first-class are semantically related. In some cases you can use "Infrequent" instead an adjective phrase "First-class".

Infrequent adjective - Not often occurring or repeated.

First-class and infrequent are semantically related. Sometimes you can use "First-class" instead an adjective "Infrequent".

Nearby Word: infrequently