1. noun
a) Any wooden block used as a wedge or filler
b) Any fitting or fixture used to restrict movement, especially movement of a line; traditionally was a fixture near a bulwark with two horns pointing towards each other, with a gap between where the line can be inserted.
2. verb
a) To stop or fasten, as with a wedge, or block; to scotch.
b) To insert a line in a chock.
Wikipedia foundation.