What is the meaning of 'Soporific'?

Soporific (noun), (adjective)
English Meaning: Causing sleep or making a person want to sleep.
Bangla Meaning: নিদ্রাকর (পদার্থ, পানীয় ইত্যাদি)।

Synonyms: Tranquillizer (নিদ্রা উদ্রেককারী ওষুধ), Drowsy (তন্দ্রালু), Sleepy (নিদ্রালু; নিদ্রাতুর).
Antonyms: Stimulant (উদ্দীপক), Invigorating (তেজস্কর; তেজস্বী; উৎসাহদায়ক).

Other words: 
- Anomalous: Different from what is usual, or not in agreement with something else and therefore not satisfactory.
- Substantiate: To show something to be true, or to support a claim with facts.
- Guileless: Honest and direct.

Example Sentence: ‘It is very often necessary to give medicines like vitamin tablets or soporific tablets.’