definition · to define

How would you define "happiness"?

What I’m getting at is that Zamenhof not only built a linguistic object, but that behind that was an idea — an idea of brotherhood, a pacifist idea. That strength of an ideal — for which Esperantists were even persecuted under Nazism and Stalinism — is still conserved by the community of Esperantists. One cannot say that it has failed, but one thing needs to be said: the reason why any language is successful is always indefinable.

What do you think of this word's definition?

That Space, as our mathematicians have it, is spoken of as having three dimensions, which one may call Length, Breadth, and Thickness, and is always definable by reference to three planes, each at right angles to the others.

The concept of “Internet addiction” implies that “the Internet” is some sort of definable activity.