The term 'agate-scarce' is a compound of 'agate' and 'scarce.' 'Agate' refers to a type of semi-precious stone, often used to describe something small or rare, and 'scarce' means 'hard to find.'

'Agate-scarce' was used in 19th-century English as an intensifier for 'scarce,' drawing on the rarity of agate stones to emphasize the degree of scarcity.

Initially, it meant 'as rare as an agate,' but over time it evolved to mean 'extremely scarce' in general usage.