Amir narrates from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that the meaning of returning is that he has intercourse.
The Shaykh (may Allah have mercy on him) said: Al-Hasan (may Allah have mercy on him) said: The meaning of returning is intercourse; if he has an excuse, such as illness or imprisonment, then returning with his tongue suffices.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الإيلاء / 15235