Straight-a Definition
    noun
  
 (education) Grades or marks that are consistently A's.
He always gets straight A’s; he must study a lot.
 Wiktionary 
    adjective
  
 (education) Pertaining to one who makes straight As.
 Wiktionary 
Other Word Forms of Straight-a
Noun
Singular:
 straight-aPlural:
 straight-as




