This is the 2307th most frequent Japanese word.
いつか
"いつか" means "someday" or "at some point in the future."
Here,"いつか" is used to express a wish or longing to do something in the future, at an unspecified time.
いつか日本に行きたいです。
I want to go to Japan someday.
In this context, "いつか" is used to express hope or desire for an event to happen in an indeterminate future time.
いつか会えるといいですね。
I hope we can meet someday.
Here, "いつか" refers to an unspecified time in the past when an event occurred.