ततस्तद्वृत्तिनैश्चल्यं कुंभकः प्राणसंयमः ।अयं चापि प्रबुद्धानामज्ञानां घ्राणपीडनम् ॥ १२० ॥
In plain words
After that, the total stillness of that movement of mind — that is kumbhaka, the real holding of prāṇa. And this is what it is for those who have woken up. For the ignorant, it is squeezing the nose shut.
Close to the Sanskrit
Thereafter, the immobility of that mental modification is kumbhaka, the restraint of prāṇa. And this indeed is of the awakened; of the ignorant, it is a squeezing of the nose.