This is the 704th most frequent Japanese word.
いか
"いか" means "squid" in English.
'いかが' is a polite form of the word 'how', used in offering or asking opinions.
いかがでしょうか？
How about this?
'いか' here is a noun that means 'squid'.
海でいかを捕まえた。
I caught a squid at the sea.
'以下' in this context means 'below' or 'the following' and is used to indicate subsequent items or points.