And very next section:
"If you compile Redict’s source code into an executable form and distribute this executable form to others you are required to include a copy of the Redict source code and any modifications to it licensed under the LGPL."
Let's be real: Especially in the EU, the definition of distribution of derivative works is typically so strong that it's super risky to use any copyleft license and I personally (e.g. consulting for large companies) see huge issues with compliance whenever this happens.
In other words, it doesn't even matter what the current intention of using this license is regarding commercial use (but not distribution?)... I would not recommend to use this commercially for multiple reasons including risk, career but also the fights to be had with legal compliance.