Definition

1. Noun:
   • The ABO blood type containing both A and B antigens: "group AB" refers specifically to one of the four main human blood groups in the ABO system, characterized by red blood cells that have both A and B antigens on their surface and by plasma that contains neither anti-A nor anti-B antibodies.

Usage

• "Group AB" is a technical, scientific term used primarily in medicine, biology, and healthcare contexts.
• It functions as a compound noun where "group" is the head noun and "AB" is a fixed, capitalized modifier specifying the type.
• It is typically used with determiners like "the" or possessives, or preceded by prepositions like "with" or "of."

Examples

• Noun:
  • Patients with group AB blood are considered universal plasma donors.
  • The distribution of group AB varies among different populations.
  • Her blood type was identified as group AB.

Advanced Usage

• "group AB positive/negative": This specifies the Rh factor (Rhesus factor) in addition to the ABO type.
  • He is group AB positive, making his red blood cells compatible with all ABO types for plasma donation.

Variants and Related Words

• AB: Often used informally as a shorthand for "blood type AB" or "group AB."
  • "What's your blood type?" "I'm AB."
• Blood group AB: A fuller, more formal synonym.
• Type AB: A common alternative phrasing.
• ABO system: The classification system that includes groups A, B, AB, and O.

Synonyms

• Blood type AB
• Blood group AB
• Type AB

Notes on Meaning

• This term has a single, precise scientific meaning related to immunology and transfusion medicine. It does not have idiomatic or phrasal verb uses.
• Individuals with group AB blood can receive red blood cells from donors of any ABO type (A, B, AB, or O) but can only donate red blood cells to other AB recipients. Conversely, their plasma can be donated to recipients of any ABO type.

Noun

1. the blood group whose red cells carry both the A and B antigens