- a prefix occurring in loanwords from Greek (diabetes; dialect) and used, in the formation of compound words, to mean “passing through” (diathermy), “thoroughly,” “completely” (diagnosis), “going apart” (dialysis), and “opposed in moment” (diamagnetism).
- through, throughout, or duringdiachronic
- (in botany) at right anglesdiatropism
- in opposite or different directionsdiamagnetism
before vowels, di-, word-forming element meaning “through, thoroughly, entirely,” from Greek dia-, from dia “through, throughout,” probably from the root of duo “two” (see two) with a base sense of “twice.”
- A prefix meaning through or across, as in diameter, the length of a line going through a circle.