期 is used as a measure word for issues/installments: 第一期 (first issue), and as a suffix in time words: 学期 (semester), 日期 (date), 星期 (week), 长期 (long-term), 短期 (short-term).
usage
期待 (qīdài) means 'to look forward to' and 期望 (qīwàng) means 'to hope/expect' — both from the meaning of 期 as 'to expect.'