Sentence:  One day last week , Nixon faced a painful constitutional chore that required him to <WSD>officiate</WSD> at a joint session of Congress to hear the official tally of the Electoral College vote , and then to make `` sufficient declaration '' of the election of the man who defeated him in the tight 1960 presidential election . 
Meaning of the word marked with <WSD> tags:  perform duties attached to a particular office or place or function