English cousins need degrees and removals to stay precise
A first cousin is your parent's sibling's child; more broadly, English kinship calls cousins anyone two or more generations from a shared ancestor without being siblings. Degree counts steps from that ancestor; removal marks generation gaps. One person can therefore own hundreds of living cousins.
Kinship counts as cousins any two people who share an ancestor two or more generations back, provided neither descends from the other, they are not siblings and neither is the other's aunt, uncle, niece or nephew. Degree is the smaller of the two distances to the common ancestor minus one, and removal is the difference between those distances. A first cousin with no removal is also called a full cousin or cousin-german, and medicine and law class first cousins as third-degree relatives.
Mennonite families and others sometimes mark the direction of removal with cousin-uncle or cousin-nephew, while some speakers say up or down instead. A grandcousin is a first cousin twice removed, and a kissing cousin is a distant relative close enough to be greeted with a kiss. Maternal and paternal cousins need not be reciprocal, since one person's maternal cousin can be the other's paternal cousin, whereas parallel cousins, from same-sex siblings, and cross cousins, from opposite-sex siblings, always are.
When two siblings marry two siblings from another family, their children are double first cousins who share both sets of grandparents. Half cousins descend from half-siblings and share a single grandparent, and cousins can even share three grandparents, as Baldwin V of Jerusalem and Maria of Montferrat did. Step-cousins and cousins-in-law extend the term beyond blood. Genetically, relatedness halves with each generation of separation, so first cousins, linked through two shared ancestors four steps apart, have a coefficient of one-eighth.
Source: Cousin
