Eight
numeral
When a vocab is a single kanji it usually steals its meaning from its kanji as well. Same goes for this vocab word. It means eight.
When a vocab is a single kanji and all alone like this, it's usually going to use the kun'yomi. But, because this is a number (exception) it uses the on'yomi instead, meaning you already know the reading from when you learned the kanji!
八人
eight people
八ミリ
eight millimeters
八メートル
eight meters
これは八ページのエッセイです。
This is an eight-page essay.
トイレットペーパーが八ロールしかない。
There are only eight rolls of toilet paper.
パパは八トントラックのドライバーなんです。
Dad is an eight-ton truck driver.