Prodigal, a.
Etymology: [L. prodigus, from prodigere to drive forth, to squander away; pro forward, forth + agere to drive; cf. F. prodigue. See Agent. ]
Given to extravagant expenditure; expending money or other things without necessity; recklessly or viciously profuse; lavish; wasteful; not frugal or economical; as, a prodigal man; the prodigal son; prodigal giving; prodigal expenses. In fighting fields [patriots] were prodigal of blood. Dryden.
Syn. -- Profuse; lavish; extravagant; squandering; wasteful. See Profuse.
1 other Webster entry under this spelling
Prodigal, n.
One who expends money extravagantly, viciously, or without necessity; one that is profuse or lavish in any expenditure; a waster; a spendthrift. "Noble prodigals of life." Trench.
Shades of meaning
Fernald lists prodigal only as an antonym, under avaricious.
He lists it without comment; the entries above explain its neighbors.