The thick fog hushed the waves like an old wool sweater.

That wool sweater you're wearing?

For ceremonial, winter or certain indoor functions a black wool sweater and a black tie are also worn.

Gap can do pure wool sweaters for less than 40 quid and cashmere for well under 100, so why can't everyone else?

The uniform was designed as a layered system, meant to be worn over the wool shirt and trouser and in conjunction with a wool sweater and liners in colder weather.