The synonym of "Zeal" is -

• Zeal (Noun).
- English meaning: Great energy or enthusiasm connected with something that you feel strongly about.
- Bangla meaning: সতেজতা ও উদ্দীপনা।

• Synonym: Enthusiasm, Passion, Devotion, Verve.
• Antonym: Indifference, Apathy, Coolness, Passivity.

অন্যদিকে,
Apathy - সমবেদনা বা আগ্রহের অভাব,
Flash - আলোর ঝলক, চমক;
Eagerness - আগ্রহ,
Illegal - বেআইনি, অবৈধ।

Source: Merriam & Webster Dictionary, Oxford Dictionary, Accessible Dictionary.