What is the origin of "out of sight" or "outa sight" in the sense of amazing/unbelievable?

Solution 1:

It means "beyond the range of sight" and hence very high, very far, or great, exceeding limits or boundaries; this isn't the same as meaning hidden. In this metaphorical sense (not relating to sight), it dates to the 19th century, the 1830s or so.

The OED has an entry on out of sight, adjective and adverb, and it traces the development through three meanings.

1. "Beyond the range of sight". This can mean hidden or absent but as often means disappeared into the distance. There are very old examples: "When man is out of sight, soon he passeth out of mind" is from Thomas a Kempis c. 1500 (I modernised the spelling). Also, from 1619 "As soon as I was out of sight, I walked further towards the East." From 1745 "She soars clear out of sight." So there's often a sense of disappearing into the sky or exceeding boundaries or going far away, not merely being hidden or going into a dark corner. This leads to the later senses of excelling or exceeding rivals. George Eliot in 1836 uses it with some metaphorical import, implying vast distances and sublimity: "Walking through her own furlongs of corridor and under her own ceilings of an out-of-sight loftiness."

2. "Extremely well; beyond all comparison." The OED says this is originally American slang (although most of its examples are British); there is one example from 1835 onwards but more commonly late 19th century; it says the phrase is now rare as an adverb but still common as an adjective. Examples 1845 "In most respects my situation is out of sight more suitable than it was at Craigenputtock." 1880 "Under the old management, it was out of sight the most comic journal in England." 1927 "The corn we raise is our delight, / The melons, too, are out of sight." The metaphorical extension seems fairly obvious, but it's interesting to look at sense 3.

3. As an adverb, slang term from 1839 "To a great degree; to the limit of endurance; utterly; completely." 1839: "She'll talk you out of sight." Also people getting beaten "out of sight" from 1844 and 1890. This is listed as slightly later than sense 2 but in view of the closeness of dates and the fact that there are more examples of it from the mid 19th century than there are of sense 2, it's possible it's slightly older, and that 2 and 3 are closely connected. "Out of sight" equalling "very far" is a natural metaphor from the limits of human vision.

Sources:

• "out of sight, adv., adj., and n." OED Online. Oxford University Press, December 2021. Web. 20 December 2021.
• Phrase Finder
• Out of sight, The Free Dictionary