cotton:  As with knowledge of the plant, its name cotton came to Europe from the Middle East. It originated in Arabic qutn, which passed via Spanish into the other languages of Europe. English acquired it via Old French coton. The verbal idiom cotton (on) to ‘come to understand’ developed in the 20th century from an earlier ‘harmonize, agree’. This in turn has been traced back to a still earlier ‘prosper’, which seems to have originated in the 16th century with the notion of the successful raising of the nap on cotton cloth.
late 13c., from Old French coton (12c.), ultimately (via Provençal, Italian, or Old Spanish) from Arabic qutn, a word perhaps of Egyptian origin. Philip Miller of the Chelsea Physic Garden sent the first cotton seeds to American colony of Georgia in 1732. Also ultimately from the Arabic word, Dutch katoen, German Kattun, Provençal coton, Italian cotone, Spanish algodon, Portuguese algodão. Cotton gin is recorded from 1794 (see gin (n.2)).