Vaisesika Sūtra 1.2.8

द्रव्यगुणकर्मभ्योऽर्थान्तरं सत्ता ॥८॥

dravyaguṇakarmabhyō'rthāntaraṁ sattā ॥8॥

[द्रव्य गुण कर्मभ्यः अर्थान्तरं सत्ता॥
dravya = substances; guṇa = qualities; karmabhyaḥ = actions; arthāntaraṁ = difference in the meaning; sattā = is truth, i.e. existence, being.॥]

The difference in the meaning between substances, qualities, and actions is 'Satta' i.e. existence.