Another way of saying "within the day". Intraday price movements are particularly important to short-term traders looking to make many trades over the course of a single trading session. The term intraday is occasionally used to describe securities that trade on the markets during regular business hours, such as stocks and ETFs, as opposed to mutual funds, which must be bought from a dealer.
Taobiz explains Intraday
This term is often used to refer to the new highs and lows of a security. For example, "a new intraday high" means a security reached a new high relative to all other prices during a trading session. In some cases, an intraday high can be equal to the closing price. Traders pay close attention to intraday price movement by using real-time charts in an attempt to benefit from the short-term price fluctuations.