That is very interesting, Paul. I can see that a word meaning "seesaw" could easily change meaning and became "person going up and down as if on a seesaw". But can you find any references to the "seesaw" meaning? Or is it conceivably something you have dreamed up yourself?
   I have had a glance in my own dictionary, and googled on a couple of entries, but everything I have seen has been in the rumbustious, jumping up and down area: no seesaws. I must have another browse.