[georgiadevildog]

carrot, carat, karat, caret

cents, scents, sense, since

medal, metal, meddle, mettle

That's all I can muster.

[Tax-chick]

None of those is really a "4," if you enunciate.

[arthurus]

cents, scents, sense, since

Since only fits in this progression in some parts of the South where all four words are pronounced "sints" or "see-ints."

[arthurus]

medal, metal, meddle, mettle

Three of these, at least, come from the same root and have essentially the same meaning. Meddle is different.