This is the 1306th most frequent Japanese word.
素
"素" (su) means "plain," "basic," "element," or "natural essence."
素直 is used here to mean 'straightforward', showing how '素' contributes to describing personality characteristics.
彼女の素直な性格が好きです。
I like her straightforward personality.
素 is used here as 'base', referring to the core ingredient or foundation of preparation.
この料理の素は何ですか？
What is the base of this dish?
素敵 means 'wonderful' or 'lovely', incorporating '素' to convey a sense of beauty or charm.