Term describing a lack of general maintenance. Similar to grime, dust or decay in the real world.
Applied to a wiki, cruft describes both low readership and low maintenance. A web page can have linkrot because a hyperlink is obsolete or generally dated. A page which is crufty may have low utility or popularity.
One method of avoiding general cruft is to wikify many topics together, allowing an interested reader to browse between several topics, possibly bumping into topics which would otherwise be unknown. Topical central pages which have lists of links are one way to bind many related or semi-related pages together.
Of course, a large wiki, or one with a small readership, will have problems with cruft, but wiki advocates would say that cruft isn't too much of a concern; an unused page and doesn't really impact readers. Topic popularity will often assure that cruft is kept at bay.