She waited ___ customers all day at the department store.

• Complete sentence: She waited on customers all day at the department store.
- Bangla Meaning: সে সারাদিন ডিপার্টমেন্ট স্টোরে গ্রাহকদের সেবা দিয়েছে।

• Wait on/upon someone/something
- English Meaning: to serve food and drink, especially to customers in a restaurant; to make a formal call on; to serve someone.
- Bangla Meaning: সেবা/খেদমত করা; ফরমাশ খাটা; পরিচারক/অনুচররূপে কাজ করা। (প্রাচীন প্রয়োগ) সাক্ষাৎ করতে যাওয়া।

• More examples:
- The staff who waited on us at dinner were excellent.
- She waited on tables (= served meals as a job) to earn some extra money.

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