1. extremely tight or secure
Usage: informal
2. very close or intimate in relationship
Usage: informal; slang

Examples

• The jar lid was supertight and wouldn’t budge.
• Make sure the bolts are supertight before using the equipment.
• Those two have been supertight friends since childhood.
• The security at the event was supertight.
• Her supertight schedule left no room for breaks.
• The band members are supertight after years of touring together.