Good At
Skilled At, Strong Point, Specialty, Forte
noun, な adjective, の adjective
When you're able to acquire ideas at a fast rate, you must be familiar with whatever it is you're doing. If you acquire ideas in this way, there's a good chance you're good at or skilled at this action.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
一番得意な料理は何ですか。
What is your specialty dish?
彼はプログラミングが得意です。
He is good at programming.
彼は物事を分類するのがあまり得意ではありません。
He isn't very good at classifying things.