Sake is one of those nebulous yet specific words that are employed in a limited number of circumstances. This post discusses its origin and uses.
Sake (from the Old English term sacu, meaning “guilt”), which primarily means “end” or “purpose,” is used most transparently in phrases beginning “for the sake of”: “For the sake of appearances” pertains to something done solely to result in positive perception rather than sincere, practical benefit, while “for the sake of argument” introduces a hypothetical proposition that involves a contrary viewpoint, as in, “For the sake of argument, let’s say that what appears to be murder was an accident.”
Meanwhile, “for the sake of it” is an idiomatic phrase meaning “for no particular reason”; hell, as a meaningless intensifier, often substitutes sake in this usage. Conversely, “for old time’s sake” pertains to something done as a nod to nostalgia.
Also, one can write “for (one’s) sake,” as in “For John’s sake, we didn’t tell him about the incriminating letter,” where sake means “benefit” or “welfare.” But “for God’s sake”/“for Christ’s sake” (the latter sometimes styled “for chrissake”) is an expression without meaning except to express some heated emotion, such as exasperation.
For the sake of euphemism, such a phrase is often bowdlerized to something like “for Pete’s sake,” inspired perhaps by St. Peter’s name or by the expression “for pity’s sake” as part of a plea for mercy. Variations include “for heaven’s sake” and “for goodness’ sake”; note the apostrophe indicating the genitive state of goodness, signaling that the sake “belongs” to goodness. (Even in content in which the style is for an s to follow an apostrophe in possessive case, this idiomatic style prevails.) Conversely, the phrase is sometimes rendered more forceful by replacing the middle word with a word equivalent to brandishing one’s middle finger.
The compound namesake originally meant, literally, “one named for the sake of another,” referring to a child named after a parent or another adult to honor that person; now, its meaning extends to “anyone sharing one’s name.” On that model was keepsake coined; it refers to something originally belonging to, or otherwise associated with a deceased or departed person that is kept by another to honor the first person’s memory.
The word forsake (past tense forsook, and forsaken as a past participle and an adjective), meaning “abandon” or “renounce,” stems from the Old English intensifying prefix for-, meaning “completely,” and sake in its original sense of “accuse” or “dispute.” The adjective godforsaken—literally, “abandoned by God”—refers to someplace or something neglected or remote.
Sake is also seen in the expression “Art for art’s sake,” referring to the sentiment that art exists on its own merits and requires no justification.