elder, older Definition

elder¹
adj

1. Older.

Thesaurus: senior, older, first-born; Antonym: younger.
2. Used before or after a person's name to distinguish them from a younger person of the same name.

Form: the elder

noun

1. A person who is older.
2. An older person, especially someone regarded as having authority.

Form: elders (often)
3. In some tribal societies: a senior member of a tribe, who is invested with authority.
4. In some Protestant Churches: a lay person who has some responsibility for pastoral care and decision-making.

Etymology: Anglo-Saxon eldra, comparative of ald old.

Info:

Older is the more general adjective. Elder is restricted in use to people, and is generally only used as an adjective in the context of family relationships, as in an elder brother/sister. It is always used before a noun or pronoun, or in the elder. Elder is not used in comparisons with than: She is older (not elder) than me.