Sentence:  ... substitution of a carboxylate would be expected to destabilize the dritterionic mesomer that contributes to the singlet valence bond description as the benzyne geometry becomes more <WSD>bicyclic</WSD>. 
Meaning of the word marked with <WSD> tags:  Having two rings of atoms in the molecule; the rings may be fused, as in naphthalene, or separate, as in biphenyl.