tough

The Old English word 'tōh' described physical matter that resisted cutting: sinew, leather, dense fiber. It derives from Proto-Germanic tanhu-, a root shared by Old High German 'zāh' and Old Saxon 'tāh,' both meaning firm or unyielding. Anglo-Saxon writers applied it to rope, hide, and the grain of wood. The extension to human character came at least two centuries later.

By the 12th century, Middle English writers were applying the word to men who endured without breaking. The spelling drifted from 'tōh' toward 'tough' as the Great Vowel Shift, running roughly from 1400 to 1700, reshaped English vowels. Chaucer's contemporaries would have recognized the word but pronounced it closer to 'toch' than to the modern sound. The meaning had already crossed from material to moral.

Shakespeare used 'tough' with precision rather than frequency. By the 18th century, compound phrases appeared: 'tough going,' 'tough luck.' These phrases treated difficulty as a substance one could push against, which is exactly the word's original meaning applied to circumstance. The metaphor was so natural that speakers stopped noticing it was a metaphor.

American English amplified 'tough' in the 19th century, using it for frontier terrain and frontier character in the same breath. The 20th century produced 'tough love,' 'tough guy,' and 'tough call,' each one a variation on the same ancient idea of resistance without fracture. The word kept its core meaning across every register it entered.