moment-by-moment

The phrase 'moment-by-moment' is a modern English compounding construction that leverages repetition for emphasis. Its core component, 'moment', entered English via Old French from the Latin momentum, which originally denoted a particle capable of causing movement or a turning point, derived from the verb movere (to move). This connection to movement and a brief, precise point in time evolved into its current meaning of a very short period. The preposition 'by', of Germanic origin, here signifies succession or progression ('one after another'). The logic of the compound is transparently literal: it describes something considered at each successive instant, creating a sense of continuous, immediate progression or attention.

This is a hyphenated compound phrase. It is formed by repeating the noun 'moment' and connecting them with the preposition 'by'. 'Moment' originates from Latin momentum (movement, particle of time, importance), from movere (to move). 'By' originates from Old English bī (near, at, during).