"Several centimetres" means a few or more than one unit of measurement called centimetres, which is a metric unit used to measure length or distance. Full definition
Although the snakes struck out less often, they could «strike at and capture fish swimming several centimetres from the head and tentacles,» Catania says. (newscientist.com)
Around 90 % of mums - to - be get stretch marks, they usually appear on the breasts, thighs and belly and can vary in width from 1 - 10 mm and can be several centimetres long. (bounty.com)
Lars Peter Nielsen and his colleagues at Aarhus University in Denmark have found that tens of thousands of electric bacteria can join together to form daisy chains that carry electrons over several centimetres — a huge distance for a bacterium only 3 or 4 micrometres long. (newscientist.com)