'Reduce' is Latin for 'lead back' — making smaller came from returning something to a simpler state.
To make smaller or less in amount, degree, or size; to bring to a simpler or more basic form; in chemistry, to add electrons to a substance.
From Latin 'redūcere' (to lead back, to bring back, to restore), from 're-' (back, again) and 'dūcere' (to lead). The literal meaning is 'to lead back' — to bring something back to a former or more basic state. The modern sense of 'making smaller' developed through the idea of 'leading back' something to a simpler
In chemistry, 'reduction' means the opposite of what the word seems to suggest — it means gaining electrons, not losing them. The term dates from metallurgy: 'reducing' a metal ore meant extracting the pure metal by leading it 'back' from its compound state. When chemistry formalized this as electron gain, the etymological name stuck even though the substance actually increases in electron count