Update: This site used to have a domain name konstruktors.com.
Konstruktors is a Latvian word for a metal construction set for children. Such toys have been around since the beginning of the previous century and are known by names such as Meccano, Erector and many others. They consist of different metal plates and strips with equally spaced holes, as well as axes, wheels, screws, bolts and the necessary wrenches and screwdrivers. One could build anything from cars to bridges and helicopters with it.
Konstruktors is also a constructor — person who is designing something.
Is it plural?
Letter ‘s’ at the end of the word doesn’t mean that it is plural, but rather indicates the grammatical gender (in this case masculine).