1. impossible to use up completely; endless
2. having unlimited energy or enthusiasm; tireless

Examples

• The country’s oil reserves seemed inexhaustible until the 1970s.
• Solar energy provides an inexhaustible source of power.
• She has an inexhaustible supply of creative ideas.
• His inexhaustible enthusiasm motivated the entire team.
• The library’s collection appeared inexhaustible to the young student.
• Her inexhaustible patience with children made her an excellent teacher.
• The ocean contains an inexhaustible amount of water.