Key difference: The term younger is a comparative form of young, which basically means more young. Similarly, the term elder is a comparative form of old, which basically means older in age. The terms younger and elder are opposites, as well as complementary words, which means that they are often used together and mean the opposite of each other.

 The terms younger and elder are commonly used in relations to age. The term younger is a comparative form of young, which basically means more young. The term is used to indicate that something is less in age than something else. The term can also be used to refer to something possessive such as younger days. It may also be used to indicate a gap of years, for example: Mary is five years his younger. This basically means that Mary is five years younger than him.

Similarly, the term elder is a comparative form of old, which basically means older in age. The term is used to indicate that something is more in age than something else. Similar to younger, elder can also be used to refer to something possessive such as elder days, elder siblings, etc. Elder also indicates a gap of years however increasing in age. For example: Tom is five years Mary’s elder. This basically means that Tom is five years older than Mary. Additionally, elder can also refer to superior in rank, office, or validity, such that the previous sentence ‘Tom is five years Mary’s elder’ when talking about coworkers rather than siblings, can also indicate that Tom had been working here for five years longer than Mary and may have nothing to do with age.

The terms younger and elder are opposites, as well as complementary words, which means that they are often used together and mean the opposite of each other. While, younger means younger, elder means older.

 The terms younger and elder are also commonly used in relation to siblings. The terms are used to identify the ages of the siblings. Hence, the sibling who is younger than the other is considered as the younger sibling, or younger sister or younger brother. Whereas, the sibling who is older than the other is considered to be the elder sibling, or elder sister or elder brother.

The terms may also be used as part of name titles. For example: John the elder, or John the younger. They are commonly used when two people share the same name. Often, children are named after their parents, or family names. Hence, the titles Younger and Elder can distinguish whether the person is talking about the older one or the younger one.

Comparison between Younger and Elder:

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