I. auc ‧ tion 1 /ˈɔːkʃ ə n $ ˈɒːk-/ BrE AmE noun [uncountable and countable]
[ Date: 1500-1600 ; Language: Latin ; Origin: auctio 'increase' , from augere ( ⇨ ↑ augment ); because the money offered increases ]
a public meeting where land, buildings, paintings etc are sold to the person who offers the most money for them
at auction
The house was sold at auction.
put something up for auction (=try to sell something at an auction)
This week 14 of his paintings were put up for auction.
auction house (=a company that arranges auctions)
II. auction 2 BrE AmE ( also auction off ) verb [transitive]
to sell something at an auction