The antonym of the word 'Turbid' is -

• Turbid (adjective)
English Meaning: (of a liquid) not transparent because a lot of small pieces of matter are held in it.
Bangla Meaning: (১) (তরল) ঘন, ঘোলাটে; ঘোলা; আবিল, কর্দমাক্ত; পঙ্কিল; the turbid floodwaters of the river.

Synonyms: Polluted (দূষিত), Thick (পুরু), Dense (ঘন), Dark (অন্ধকার), Impure (অশুদ্ধ)।

Antonyms: Clear (পরিষ্কার), Transparent (স্বচ্ছ), Bright (উজ্জল), Neat (পরিষ্কার), Light (হালকা)।

Example Sentence:
1. Several different species of fish inhabit these turbid shallow waters.
2. Here, the shoreline can be obvious, if you realize that the water is very turbid.

Source:
1. Cambridge Dictionary.
2. Accessible Dictionary by Bangla Academy.