month-by-month

The term 'month-by-month' is a modern English compound phrase, a reduplicative construction used for emphasis on regular, sequential intervals. Its first element, 'month', traces back to Old English mōnaþ, which is derived from the Proto-Germanic mēnōþs, itself connected to the word for 'moon', reflecting the ancient lunar basis for measuring time. The preposition 'by', from Old English bī, signifies proximity, agency, or manner, and in this construction, it denotes the method or sequence of progression. The repetition of 'month' creates a distributive and iterative sense, evolving from the literal concept of time measured by the moon's cycles to an abstract adjectival and adverbial phrase denoting systematic, recurring monthly action or calculation.

This is a compound phrase formed from the English word 'month' (Old English mōnaþ, from Proto-Germanic mēnōþs, related to 'moon') and the preposition 'by' (Old English bī, of Germanic origin). The phrase is reduplicated to indicate repetition.