Velcro

A trademark used for a fastening tape consisting of a strip of nylon with a surface of minute hooks that fasten to a corresponding strip with a surface of uncut pile. This trademark sometimes occurs in print in lowercase.

The name is a contraction of "velour crochet" - French for "pile hook" (more or less).

Note that most Velcro has the habit of not holding well when wet. For that reason, other types of fastener are preferred. There are industrial versions of Velcro that are somewhat stronger as well as a marine fastener from 3M that is considerably stronger, especially when wet. The latter is basically a plastic strip with little mushroom-shaped blips on the surface. Both surfaces to be stuck together are the same and the mushroom thingies lock onto each other.