Definition of high-calibre in US English:

high-calibre

(US high-caliber)

adjective

  • 1Of a high standard; high-quality; (of a person) highly capable; very skilled, experienced, etc.

  • 2(Of a gun) having a large bore or calibre; (also of a bullet or other projectile) having a large diameter.

Origin

Late 19th century; earliest use found in The Boston Globe.