Meaning : Being up to particular standard or level especially in being up to date in knowledge.
Example :
Kept abreast of the latest developments.
Constant revision keeps the book au courant.
Always au fait on the latest events.
Up on the news.
Synonyms : abreast, au courant, au fait
Up on ka meaning, vilom shabd, paryayvachi aur samanarthi shabd in Marathi. Up on ka matlab kya hota hai?