infrequent

adj.不经常的

influential, influenza, influx, inform, informal, informality, informally, informant, information, informative, informed, informer, infra, infra dig, infra-, infra-red, infraction, infrared, infrastructure, infrequency, infrequently, infringe, infringement, infuriate, infuriating, infuriatingly, infuse, infusion, ingenious, ingeniously, ingenue, ingenuity, ingenuous, ingenuously, ingenuousness, ingest, ingle-nook, inglorious, ingloriously, ingoing,