A

1. (as a medieval Roman numeral) 50 or 500
2. Ampere (SI unit)

A¹ or a /ā/

1. The first letter in the modern English alphabet as in the Roman, etc (see aleph and alpha), with various sounds, as in name, path, bad
2. The sixth note of the diatonic scale of C major (music)
3. The key or scale having that note for its tonic (music)
4. One of the four blood types in the ABO blood group system
5. The designation of the principal series of paper sizes, ranging from A0 (841×1189mm) to A10 (26×37mm)
6. In road-classification, followed by a number, the designation of a major or trunk road, as in the A60
7. In hexadecimal notation, 10 (decimal) or 1010 (binary)
8. The highest in a category or range
9. Something or someone of the first class or order, or of a class arbitrarily designated A
10. Anything shaped like the letter A

Aˈ-line adjective

(of clothing) narrow at the top and widening evenly to a full hemline

• rectipetalies
• rectipetalities
• rectipetality
• rectipetaly
• rectirostral
• rectiserial
• rectitic
• rectitis
• rectitises
• rectitude
• rectitudes
• rectitudinous
• recto
• recto-
• rectocele
• rectoceles
• rector
• rectoral
• rectorate
• rectorates
• rectoress
• rectoresses
• rectorial
• rectorials
• rectories