(No, I have no idea why these things pop up in my mind.)
From Wikipedia:
Houndstooth, hounds tooth check or hound’s tooth (and similar spellings), also known as dogstooth, dogtooth, dog’s tooth, or pied-de-poule, is a duotone textile pattern characterized by broken checks or abstract four-pointed shapes, often in black and white, although other colours are used.
A bit of history from the Wikipedia entry:
… Contemporary houndstooth checks may have originated as a pattern in woven tweed cloth from the Scottish Lowlands, but are now used in many other woven fabric aside from wool. The traditional houndstooth check is made with alternating bands of four dark and four light threads in both warp and weft/filling woven in a simple 2:2 twill, two over/two under the warp, advancing one thread each pass. In an early [use of] houndstooth, De Pinna, a New York City–based men’s and women’s high-end clothier …, included houndstooth checks along with gun club checks and Scotch plaids as part of its 1933 spring men’s suits collection. The actual term houndstooth for the pattern is not recorded before 1936.
A comparison of this pattern to others, from the A Tailored Suit site’s “Men’s Suits — Exploring Suit Fabric Patterns”:
(#2) Back when I wore serious men’s clothing, I was a herringbone tweed coat and paisley tie guy; but I admire the complex boldness of houndstooth
There are many wonderful color variants of the houndstooth pattern. Here, from the Brooks Brothers site, is a handsome Regent fit houndstooth sport coat in brown: