This is the 5418th most frequent Japanese word.
i
The Japanese word "i" (い) does not have a standalone meaning; it is a hiragana character used in writing and pronunciation.
Here, 'いい' means 'good' or 'nice,' used as an adjective describing 'アイディア' (idea).
これはいいアイディアですね。
This is a good idea.
In this sentence, 'いい' describes the noun '天気' (weather) as being 'nice' or 'pleasant'.
いい天気ですね。
It's a nice day, isn't it?
Here, 'いい' is used to describe the '見た目' (appearance) of '靴' (shoes) as being 'nice.'