A person who pretends to be ill in order to avoid having to work is a-

• A person who pretends to be ill in order to avoid having to work is a Malingerer.

• Malingerer (Noun)
- English Meaning: A person who pretends to be ill or exaggerates their illness to avoid work, responsibility, or duty.
- Bangla Meaning: অসুস্থতার ভান করা ব্যক্তি; দায়িত্ব এড়াতে রোগের অভিনয় করে এমন ব্যক্তি।

• Other options:
ক) Hypocrite (ভণ্ড; ভণ্ড তপস্বী): A person who pretends to have moral standards or beliefs to which their own behaviour does not conform.
গ) Imposter (ভণ্ড; ধর্মধ্বজী; ছদ্মতাপস): A person who pretends to be someone else in order to deceive others, especially for fraudulent gain.
ঘ) Pedant (অতি ধার্মিক ব্যক্তি; বিস্তারিত জ্ঞানবিশারদ): A person who is excessively concerned with minor details or rules, often in a way that is annoying to others.

Source:
1. Cambridge Dictionary.
2. Oxford Dictionary.