- The definition of a nephew is a sibling's son or a sibling-in-law's male child.
An example of nephew is your sister's son.
nephew definition by Webster's New World
- the son of one's brother or sister
- the son of one's brother-in-law or sister-in-law
- an illegitimate son, as of a medieval prelate: a euphemism
- a descendant
Origin: Middle English neveu ; from Old French ; from Classical Latin nepos ; from Indo-European base an unverified form nepot-, grandson, nephew from source Sanskrit napat, Old English nefa
nephew definition by American Heritage Dictionary
- A son of one's brother or sister or of the brother or sister of one's spouse.
- The illegitimate son of an ecclesiastic who has taken a vow of celibacy.
Origin: Middle English neveu, nepheu, from Old French nevo, neveu, from Latin nepōs; see nepōt- in Indo-European roots.