Nancy Scheper-Hughes wrote it, it's my favorite definition, it's from an old syllabus of her course at UC Berkley

Cultural Anthropology is

the intimate and personal study of human cultures, societies, and changing social, economic and political situations in an increasingly globalized world. Anthropology is intimate and personal because the field requires the anthropologist to live-in and live-with the people and communities they are trying to understand. Anthropological knowledge is gained though cultural immersion as well as through careful scholarship and learning. Beginning with the early 20th century, cultural anthropologists, some as 'explorers', some as 'scientists', some as great writers and 'public intellectuals', traveled far and wide and wrote books (called ethnographies) about the people and cultures they encountered. In these books anthropologists tried to make "the strange" and the "exotic" seem more familiar to their American, or French, or British readers. At the same time anthropologists tried to unbalance and to "make strange" what was taken for granted, what was commonsense in their own societies.