{1:18}
विरामप्रत्ययाभ्यासपूर्वः संस्कारशेषो Sन्यः
virāmapratyayābhyāsapūrvaḥ saṃskāraśeṣo ’nyaḥ
विराम प्रत्यय अभ्यास पूर्वः संस्कार शेषः अन्यः
I.K Tamini:
The remnant impression [left in the mind] after previous practice [and] on cessation of the content in the mind, is the other (type of samādhi)
The Bihar School:
The other (anya) samādhi is preceded by continued practice (abhyāsa) of stopping the content of the mind. In it the mind remains in the form of traces.
Trevor Leggett's translating Śankarācarya’s commentary:
The other [samādhi] follows on practice of the idea of stopping and consists of saṃskāra-s alone.
विराम -pause, stop, end; masc noun
प्रत्यय - idea, concept, content of mind; masc noun
अभ्यास - exercise, practice;drill; masc noun
पूर्वः - पूर्व as an adjective means initial, earlier, prior. Hhere, the visarga indicates it is being used as masc. noun, a kinship term like forefather or ancestor. Almost like the three that have gone before beget something, which in this case is संस्कार. It's a subtle difference. Even the adjective works, but use of the noun establishes a deeper link - 'born of'.
संस्कार - impressions in the mind of deeds and activities performed in a former state of existence; masc noun.
शेषः - that which remains or is left behind; masc/neuter noun
अन्यः - the other, another. The fact that this adjective has a visarga clearly indicates that it refers to a masc noun, which is [another] samādhi.
In 1:17, we learned about samprajñātaḥ samādhi which is a state of mind accompanied by reasoning, reflection, bliss and a sense of individuality. All of these indicate some activity or content in the mind. Hence we can collectively call them प्रत्ययाः When these contents are stopped. paused, ended, we have a state new state of samādhi which is called the 'other' i.e. not samprajñātaḥ therefore - asamprajñātaḥ.
I cannot stress enough that this is only a grammatically analysis and a translation based on commentaries by yogic experts. In no way does it intend to 'teach' you how to achieve samādhi. If at all, the only aim is to arouse your curiosity to find out more. Yoga has been a living tradition for longer than written History, and is transmitted through an unbroken chain of living gurus. You must learn from one such adept.