JULIAN BOND, chairman of the NAACP, got it exactly right yesterday when he said D.C. Mayor Anthony Williams was wrong to accept the resignation of a presumably loyal and competent aide who offended a subordinate by using the word "niggardly" in a conversation. Mayor Williams has said he did not believe the aide in question, David Howard, whom he had named as public advocate only days earlier, said "anything that was in itself racist." If so, Mr. Howard's resignation should have been rejected. The mayor's explanation for letting David Howard leave his administration made an unpleasant situation even worse. The mayor said that while the word "niggardly" was not a racial slur, Mr. Howard should not have used a word that could have been misunderstood. "I think what David did," said the mayor, "was {get} caught smoking in a refinery with a resulting explosion." That's a dud. If the account of what was said is true, it was the listener who wrongly attached an offensive connotation to the word. But who has been made to pay for the listener's ignorance of the word's true meaning? Not those who have spread ugly rumors about what Mr. Howard said. The person on the streets is David Howard, who quit to spare the mayor any embarrassment. Yesterday Mayor Williams indicated that he is reviewing the entire matter and may ask David Howard to rejoin his administration -- but in another capacity -- if it is determined he didn't use a racial epithet. Even that doesn't strike us as the right way to handle the situation. If, in fact, Mr. Howard did nothing wrong, the right thing to do is to put him back in the job, with a little staff housecleaning to follow. None of this means the popular mayor should be unmindful of the relatively few in this city who are ready to go off with the slightest affront, real or imagined. But as Julian Bond rightly told the Associated Press, "You hate to think you have to censor your language to meet other people's lack of understanding." David Howard should not have quit. Mayor Williams should bring him back -- and order dictionaries issued to all staff who need them.