Find the odd number / letters / word from the given alternative.

Cap
Turban
Helmet
Veil E. Hat

The odd one out is D, veil. The other options are all headwear, while a veil is a piece of cloth worn over the head and face, typically by women.

A cap is a soft, close-fitting head covering, typically with a visor and no brim. A turban is a headdress worn by some Muslim men, consisting of a long piece of cloth wound around the head. A helmet is a hard protective covering for the head, typically worn by soldiers or other people in dangerous occupations. A hat is a covering for the head, typically worn for protection from the sun or cold, or for fashion.