o.n.o. British English
(or near/nearest offer) used in advertisements to show that you are willing to sell something for slightly less money than you have said in the advertisement:
Bicycle for sale: £60 o.n.o.

[TahlilGaran] Dictionary of Contemporary English ▲

O‧no, Yo‧ko /ˈəʊnəʊ, ˈjəʊkəʊ/
(1933–) a Japanese artist and musician who was married to John Lennon. She made several records with Lennon as part of their group the Plastic Ono Band, including the song Give Peace A Chance.

[TahlilGaran] Dictionary of Contemporary English ▲