The synonym of 'Probity'

• Probity

English Meaning: adherence to the highest principles and ideals.
Bangla Meaning: সততা; সাধুতা।

Other options-
• Honesty- সততা;
• Iniquity- অন্যায়; পাপাচার;
• Probability- সম্ভাবনা; 
• Extraordinary- অসাধারণ।

So, the word 'Honesty' is synonymous with the given word 'Probity.'

Source: Cambridge Dictionary, Accessible Dictionary by Bangla Academy.