(chemistry, in combination) A substituent oxygen atom connected to another atom by a double bond / the game noughts and crosses

(chemistry) Oxygen. / (organic chemistry) Having a methylene group replaced by a carbonyl group.

(Cockney rhyming slang) The London Underground rail network.

(Ireland) Everything is satisfactory; things are fine.

(UK, slang, humorous) Of sexual intercourse: anally.

(chemistry) Alternative form of oxyacid.

plural of oxoacid

Of or pertaining to Oxford or to the University of Oxford.

A native or inhabitant of Oxford. / A student or graduate of Oxford University.

(organic chemistry) glyoxylic