Prodigal means “to spend wastefully.” So, what does that have to do with the biblical parable of the prodigal son, and what does being prodigal have to do with being a prodigy?
As it happens, there’s no connection between the two words, though an assumption that they are synonymous may lead some people to believe, erroneously, that the phrase “prodigal son” refers to an impressive young man.
For those of you who have forgotten, or never learned, the story of redemption from the Bible, the younger of two sons prematurely demands his inheritance from his father. The older man complies with his wishes, and the youth leaves home, where he foolishly fritters away his fortune.
Reduced to penury, he returns home, prepared to beg for forgiveness, but his father welcomes him and causes for a celebration. When the older son bristles at this injustice, for he has worked hard in his father’s service and has received no preferential treatment, the father explains that they should rejoice that the younger son has returned to the family fold.
Prodigal, which is derived from the Latin term prodigere, which means “to drive away or squander,” also means “lavish,” and in addition it has a sense of luxuriance that may, depending on context, be negative, neutral, or positive. However, the word is usually employed to allude to the parable in references to a redeemed returner as a prodigal son.
Prodigy, by contrast, is from a distinct Latin word, prodigium, meaning “omen or monster” (both of which stem from a precursor word that means “to warn”). The most common sense of prodigy is in reference to an unusually talented young person, although, more rarely, yet with more fidelity to its Latin roots, it may also mean “something extraordinary or inexplicable,” or “a great accomplishment.” Another rare usage is as a synonym for omen.
The adjectival form, prodigious, has lost its connection with omen (portentous is often, in its place, applied to omens) and means “strange or exciting” or, in keeping with the connection to monster, “enormous.”