Density
Concentration
noun
When something is dense to a certain degree, you’re talking about the density or concentration of something.
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.
あなたの血中アルコール濃度については追って連絡致します。
I’ll get back to you on your blood-alcohol concentration.