"in the process of defining" is correct and can be used in written English.
You could use it when explaining something that is in the process of being figured out. For example, "The team is in the process of defining a new workflow for the project."
They're still in the process of defining themselves, but in a world without definitions.
Columbia is in the process of defining retention periods for other administrative records.
NASA is currently in the process of defining plans for a new hypersonic technology program.
Just barely one year old, Podemos is still in the process of defining itself, while Syriza has been represented in the Greek parliament since 2004.
We are a young continent, and the countries are in movement, in the process of defining ourselves, and this process creates extraordinary cinematic possibilities".
Between withdrawal signals and blind militarization there is a more sustainable strategy, one that I hope the Obama Administration is the in the process of defining.
In one trust studied by the researcher, the process of defining locally meaningful measures entailed simply the collation of those that were externally demanded.
If we take into account only the direct water use of Manufacture of food and tobacco products sector in the processes of defining a policy aiming at improving its production by 20%, we will believe only in an increase of 27.5 hm3 in the total amount of water consumed by the economy as a whole.
&main=It was in this spirit that we embarked on the process of defining and securing the lineaments of our burgeoning freedom.
26 PNs supported patients in the processes of defining problems and finding solutions themselves, by applying problem-solving and reattribution techniques.
