most
UK[məʊst]US[moʊst]
adj
Greatest in amount, degree, or intensity.
adv
To the greatest extent.
pron
The greatest amount or number.
n
The greatest amount or degree.
Etymology
The word 'most' originates from the Old English 'māst', meaning "greatest, largest, most." This Old English form is a superlative built on the Proto-Germanic root 'maistaz', which is itself the superlative of the root 'maiz' (source of 'more'). This Germanic root can be traced further back to the Proto-Indo-European 'mē-', meaning "big." The semantic journey is direct: from the ancient concept of "bigness" or "greatness," the superlative form evolved to signify the ultimate degree or amount within a comparison. In Modern English, it functions flexibly across several grammatical categories, consistently conveying the sense of the highest degree or quantity.
Analysis
The word 'most' is a simplex form. It is a superlative suffix and independent word inherited from Old English 'māst', which is itself the superlative form of the root seen in 'more'.
Examples
This is the most interesting book I've read this year.
She works most efficiently in the morning.
Most of the attendees agreed with the proposal.