What's the meaning of the $-\equiv-$-like bond symbol? In the following image, $\mathrm{CH}_2$ is connected to benzene rings with a $-\equiv-$ like symbol. What's the meaning of this symbol?
This is a triple bond between two $\ce{C}$ atoms, i.e. $\ce{-C#C -}$. It is drawn that way because the carbon atoms in a triple bond are $\mathrm{sp}$-hybridised and thus exhibit a linear arrangement.