elephant
el‧e‧phant /ˈeləfənt, ˈelɪfənt/
noun [countable]
a very large grey animal with four legs, two tusks (=long curved teeth) and a trunk (=long nose) that it can use to pick things up
2. the elephant in the (living) room an important subject or problem that everyone knows about but no one mentions:
The race issue is the elephant in the room in this election.
⇨ white elephant
el‧e‧phant /ˈeləfənt, ˈelɪfənt/
noun [countable] Date: 1200-1300
Language: Old French
Origin: oliphant, from Greek elephas 'elephant, ivory'
1. Language: Old French
Origin: oliphant, from Greek elephas 'elephant, ivory'

a very large grey animal with four legs, two tusks (=long curved teeth) and a trunk (=long nose) that it can use to pick things up
2. the elephant in the (living) room an important subject or problem that everyone knows about but no one mentions:
⇨ white elephant