Mèche vs. touffe

The French words 'mèche' and 'touffe' both refer to hair, but they have distinct meanings and usages.

Mèche

'Mèche' typically refers to a thin, defined strand or lock of hair. It can also mean a wick or fuse in other contexts.
Elle a une mèche blonde qui lui tombe sur le front.
(She has a blonde lock of hair falling over her forehead.)
Le coiffeur a coupé une mèche de ses cheveux pour faire un test de coloration.
(The hairdresser cut a strand of her hair to do a color test.)
Il a une mèche rebelle qui ne veut pas rester en place.
(He has a rebellious strand of hair that won't stay in place.)

Touffe

'Touffe' refers to a thicker, bushier clump or tuft of hair. It implies a greater volume of hair than 'mèche'.
Le bébé a une touffe de cheveux drus sur le dessus de la tête.
(The baby has a tuft of thick hair on top of its head.)
Une touffe d'herbe poussait entre les dalles du jardin.
(A tuft of grass was growing between the garden slabs.)
Il a une touffe de cheveux blancs au-dessus de chaque oreille.
(He has a clump of white hair above each ear.)

Summary

While 'mèche' refers to a thin, defined strand of hair, 'touffe' describes a thicker, bushier clump. 'Mèche' is often used for intentional styling or specific parts of hair, while 'touffe' typically implies natural, voluminous growth or a distinct patch of hair.