1. able to be officially certified or verified as meeting certain standards
2. so extreme or obvious as to be beyond doubt
Usage: informal
3. mentally ill to a degree requiring institutional care
Usage: informal; potentially offensive

Examples

• The organic farm’s produce is certifiable by the agriculture department.
• Her teaching credentials are certifiable in three different states.
• That was a certifiable miracle – no one expected him to survive.
• His behavior at the meeting was certifiable madness.
• The diamond’s authenticity is certifiable by a gemologist.
• She’s a certifiable genius when it comes to mathematics.