profligate
愓 centers on reckless self-indulgence and wastefulness: a profligate person who squanders resources without restraint.
愓 combines 忄 (heart/mind) with 昜, which likely contributes the sound. The exact historical development is uncertain, but the character is associated with reckless or indulgent behavior.
The heart radical 忄 beside 昜 suggests a heart that is overly bright or expansive, like someone who spends freely and lives without restraint.
For トウ, imagine a profligate person tossing coins into a wishing well: the sound of the coin hitting the water is 'tow' (トウ), and they keep tossing without care.