Merism (Latin: merismus, ‹See Tfd›Greek: μερισμός, translit. merismós) is a rhetorical device (or figure of speech) in which a combination of two contrasting parts of the whole refer to the whole.[1]: 10 [2][3]
For example, in order to say that someone "searched everywhere", one could use the merism "searched high and low". Another example is the sword-and-sandal movie genre, a loose term for a genre of movies made principally in Italy in the 1950s and 1960s set in classical antiquity.
Merisms are common in the Old Testament. For example, in Genesis 1:1, when God creates את השמים ואת הארץ (Modern pronunciation: et hashamaim ve-et haarets) "the heavens and the earth" (New Revised Standard Version), the two parts (heavens and earth) do not refer only to the heavens and the earth. Rather, they refer to the heavens, the earth and everything between them: God created the entire world, the whole universe.[1]: 10 Other famous examples of Biblical merisms are Genesis 1:5 in which "evening" and "morning" refer to "one day" (including noon, afternoon etc.) and Psalm 139 in which the psalmist declares that God knows "my downsitting and my uprising": God knows all of the psalmist's actions.[1]: 10