adj.两星期一次的;
例句:
John does not go there every weak, just fortnightly.
约翰并非每周去那儿, 只是隔周去一次.
The institute publishes a fortnightly bulletin.
这学会会出版一份双周刊的报刊.
This magazine will appear fortnightly.
这本杂志将两周出一期.