flapper

It seems the minds of these people are so taken up with intense speculations, that they neither can speak, nor attend to the discourses of others, without being roused by some external taction upon the organs of speech and hearing; for which reason, those persons who are able to afford it always keep a flapper (the original is climenole) in their family, as one of their domestics; nor ever walk abroad, or make visits, without him. And the business of this officer is, when two, three, or more persons are in company, gently to strike with his bladder the mouth of him who is to speak, and the right ear of him or them to whom the speaker addresses himself. This flapper is likewise employed diligently to attend his master in his walks, and upon occasion to give him a soft flap on his eyes; because he is always so wrapped up in cogitation, that he is in manifest danger of falling down every precipice, and bouncing his head against every post; and in the streets, of justling others, or being justled himself into the kennel.

Small fish, and frog and fish spawn are also eaten, and the ducklings feed upon many species of animalculæ, flies, pollywogs and worms, etc., disturbed by heavy rains which wash the banks, while the young ducks are passing to the "flapper" stage.

the flapper of a porpoise

In this case, slide the collar of the flapper over the overflow tube until it seats against the bottom of the flush valve.