Sentence:  It entered her body with the ghastly intimacy of an incubus , and its particles , spreading , creeping , crawling , joined themselves into steel bands that constricted her knees so tightly that they ached ; stifled her lungs so that her breath came in harsh gasps ; clutched her throat and sucked up the moisture in her mouth so that her tongue was dry and hard and stuck to the roof of her mouth and her teeth <WSD>were</WSD> clenched together in the rigid fixture of her jaws . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)