90% of the time, speakers of English use just 7,500 words in speech and writing. These words appear in red, and are graded with stars. One-star words are frequent, two-star words are more frequent, and three-star words are the most frequent.
Kith comes from a word of Germanic origin meaning 'known'. Kin is also of Germanic origin, from an Indo-European root meaning 'give birth to'. Your kith are your friends or acquaintances, while your kin are all the people you are related to.