What is the meaning of the idiom "White elephant"?

• White elephant (Noun)
- English meaning: A thing that has no use and is no longer needed, although it may have cost a lot of money.
- Bangla meaning: কাজে আসে না অথচ দামি ও অসুবিধাজনক।

• Synonym: Throwaway, Hand-me-down, Castaway.

• উল্লিখিত অপশনগুলো,
White elephant - কাজে আসে না অথচ দামি ও অসুবিধাজনক,
Stone's throw - অতি নিকটে,
Tooth and nail - তীব্রভাবে,
Lame excuse - বাজে ওজর।

Source: Advanced Learner's Communicative English Grammar & Composition By Chowdhury & Hossain.