1. The lens of an eyepiece nearest the object; a field opera-glass.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• dield glass,
• cield glass,
• vield glass,
• gield glass,
• tield glass,
• rield glass,
• fueld glass,
• fjeld glass,
• fkeld glass,
• foeld glass,
• f9eld glass,
• f8eld glass,
• fiwld glass,
• fisld glass,
• fidld glass,
• firld glass,
• fi4ld glass,
• fi3ld glass,
• fiekd glass,
• fiepd glass

The adjective form of "field glass" is "field-glass".

The plural form of "field glass" is "field glasses"

The singular form of the word "field glass" is "field glass". The term does not change in its singular form.