Tracklements is a word for savory sauces or relishes.
They are usually served with either cold or hot meats, or with cheese.
Items such as mustard, horseradish, mint sauce, Cumberland Sauce, Brown Sauce, Ketchup, Roasted Onion Marmalade, Chili Jams, Chutney, etc. can be classed as tracklements.
The origin of the word is attributed to (or at least, was certainly claimed by) Dorothy Hartley (1892 – 1985), a food writer, in her 1954 book “Food in England.” At the time, she defined it as very often being jellies.