How can a nickname replace a person’s official name in everyday use?

A nickname replaces an official name in everyday use by serving as an informal, familiar, or descriptive alternative that often reinforces social bonds or distinguishes individuals within a community.1

Linguistically, this replacement occurs through several mechanisms:

• Morphological Alteration: Many nicknames in English are formed through clipping or truncation (e.g., "Sam" for Samantha) or by adding suffixes like -y or -ie to convey intimacy (e.g., "Danny" for Daniel).1
• Descriptive and Associative Traits: Nicknames may originate from physical characteristics, behavioral traits, or intellectual reputations. When these terms become widely recognized, they function as a primary identifier.1
• Antonomasia: This linguistic device allows a nickname to replace a name by using a descriptive phrase based on an individual’s talent or public persona, such as "the Iron Lady" for Margaret Thatcher.1
• Social Utility: In various cultures, nicknames are used to distinguish between family members sharing the same name or to foster in-group solidarity, sometimes becoming more central to social identity than formal surnames.1

Unlike pseudonyms, which are typically used to conceal identity, nicknames are generally employed to express familiarity or characterize a person within their social context.1