No, it is not. “The government doing stuff” (including seizing property) is not communism. Lots of governments seize property for all sorts of reasons. Another example, when the US was building the transcontinental rail system, there were times when it seized land that was in the path of the planned railway and gave it to the rail companies. If that made a person or system communist, then I don’t think I could name a single non-communist country in all of history.

A communist system can mean either a classless, stateless, moneyless society, the ideal that communists pursue, or it can mean a system run by communists in practice, since most communists would say that such a system cannot be implemented overnight. There is no universal, standard set of policies that makes a system communist, because communists (at least, Marxist-Leninists) believe that policies should be developed based on an analysis of a country’s specific material conditions.

Trump is not seizing parts of businesses because he’s applying some kind of Marxist analysis to conclude that that’s the best way to advance the interests of the proletariat. He’s just taking shit because he wants it and nobody can stop him. At that point, it’s like pointing at two wild animals fighting over a kill and calling them communists.

Communists may be known for nationalizing corporations but that does not mean that anyone who nationalizes a corporation is automatically a communist.