infrequent (adj.) infrequency (n.) infrastructure (n.) infrasonic (adj.) infralapsarian (adj.) infraction (n.) infra-red (adj.) infra- 表示“在下, 在下文”之義infra dig. infra (adv.) infotainment (n.) infortunate (adj.) informs v.通知;告訴;使熟悉;告發;賦特征於informer (n.) informed (adj.) informative (adj.) informational (adj.) information (n.) information n.信息;情報;資料;通知informatics (n.)