infrequent，
英语单词，主要用作为形容词，意为罕见的；稀少的；珍贵的；不频发的。
Muggings are relatively infrequent in this area.
Kids and teens who do read frequently, compared to infrequent readers, have more books in the home.
He moved on, aimlessly, and in a little while the houses thinned, and the passers-by were infrequent.