There are many familiar phrases that facilitate conversation, and are completely understood, yet the precise definition of the key word in each of these phrases may be known to very few. Our first example is the well-known phrase "He ran the gamut of all the emotions." Everyone senses that the phrase implies a range, a scale, a series; but ask what a "gamut" is and remarkably few will answer correctly that it refers specifically to the musical scale: do, re, mi, fa, etc.
Similarly, "He went scot-free" poses no difficulty in understanding, but embarrassment is certain if the meaning of "scot" is asked for. At one time, "scot" referred to a municipal tax, and anyone exempted from it was said to go scot-free. Over the years, the meaning has been extended to denote freedom from any punishment.
Anything that delights, cheers, or gratifies may be said to "warm the cockles