Profundity
Noun
ふかさ
このプールの深さを教えて下さい。
Could you tell me the depth of this pool?
コウイチの知えの深さははかり知れない。
The profundity of Koichi's wisdom is off the scale.
ビエトが、週末に百メートルの深さの落としあなをほったと自まんしていました。
Viet was bragging that he dug a hundred meter deep pit over the weekend.
This is the noun version of the kanji deep, so it means depth.
Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You already learned this reading when you learned 深い so you should be able to read this one too!