Sentence:  Any of the antithyroid drugs , of either type , if given in large enough doses for a <WSD>long</WSD> period of time will cause goitre , owing to inhibition of thyroid hormone synthesis , with production of hypothyroidism . 
Meaning of the word marked with <WSD> tags:  primarily temporal sense; being or indicating a relatively great or greater than average duration or passage of time or a duration as specified