1. Strange, odd, or unusual: Hank had a peculiar accident when he stumbled while going down the steps in the hallway.
2. Uncommon; out of the ordinary: Clara had a peculiar hobby of collecting words none of which her friends ever heard of.
3. Distinctive in nature or character from others: Mabel had a peculiar habit of eating ice cream for breakfast!

Lionel, who was from Texas, used an expression quite peculiar to Canadians and so they had a hard time understanding what he was saying!

4. Belonging exclusively to a person, group, or something: Too many dictionaries have a peculiar procedure of using another form of the word entry that is being defined; for example, "An anthropologist is someone who studies anthropology."
5. Common or normal for a certain place or circumstance: A peculiar habit of the rich ladies at the famous races in Ascot, England, is to show off their fancy hats and clothes.
6. Etymology: from Latin peculiaris as "one's own", equivalent to peculi(um), "private property" (derivative of pecu, "flock, farm animals"; literally, "property in cattle"; akin to pecus, "cattle" from which came pecunia, "money" because cattle represented wealth before money became the main element of such a status).

Black slavery in the southern U.S. before the Civil War: The peculiar institution is one main aspect in the book Gone with the Wind by Margaret Mitchell. She describes the situation of the black people being owned by white plantation masters at Tara, the O’Hara plantation in Georgia, before the war broke out between the northern and southern states in 1861.