Abarim Publications' online Biblical Greek Dictionary
The noun σκοτος (skotos) means darkness. It describes the general concept of darkness; the noun σκοτια (skotia) describes an instant of darkness (see below).
Contrary to common perception, darkness is not the opposite of light but the absence of it. And since light and enlightenment go hand in hand, ignorance is also not the opposite of wisdom but the absence of it. And ultimately, hate is not the opposite of love but the absence of it.
Light is substantial, but darkness is not. Light comes from a source, but darkness does not. Light consists of colors, but darkness does not. Light conveys information, but darkness does not. Light (or more specifically: photonic energy) comes before all things and holds all things — all things; all material things, all living things and all societies — together (Colossians 1:17). Light gives life, and darkness does not. Light and darkness relate like fullness and emptiness, and both stem from the same Creator, namely YHWH, "the One forming light and creating darkness, causing peace (שלום, shalom) and creating evil (רע, ra')" (Isaiah 45:7).
Sometimes darkness is not the result of a thing being dark, but rather of an inability of an observer to recognize light (Matthew 10:27). If a source of light is hidden from view by blindness, the result is darkness. This makes our noun σκοτος (skotos) in some way related to the noun μυστηριον (musterion), or mystery: something hidden.
The Hebrew word for to flow (what a river does) is the same as for to shine (what a lamp does), namely נהר (nahar), which means that the ancients were aware of what later would be called Special Relativity.
Our noun σκοτος (skotos), meaning darkness, is used 32 times in the New Testament, see full concordance, and from it derive:
- The adjective σκοτεινος (skoteinos), meaning dark (Matthew 6:23, Luke 11:34 and 11:36 only).
- The noun σκοτια (skotia), also meaning darkness but in the sense of an eclipsing instant rather than a general condition. This noun is used 16 times; see full concordance.
- The verb σκοτιζω (skotizo), meaning to darken, to obscure or to confuse: to knowing or unknowingly deprive others from light, insight, or social cohesion. It's used 8 times; see full concordance.
- The verb σκοτοω (skotoo), meaning to make dark, to create a general state of darkness, to broadly remove or block light, insight and social cohesion (Revelation 16:10 only).