What is the etymology of the word teeter totter?

Solution 1:

The answer to your question is that it is a regional not a generational difference.

Teeter-totter is the most widespread in America. Seesaw is specifically Southern. Dandle is from Rhode Island. Other regional variants include dandle board, teedle board, teeter, teeterboard, tilt, and tilting board. See the Dictionary of American Regional English for details.

Etymologically, the word teeter-totter was formed by reduplication of either titter or totter. It derives from titter, now a dialect form for teeter, and totter, which means the same thing. The OED also attests titter-totter, and says to see the Engl. Dial. Dict. for details. The earliest citation is:

• 1607 R. C[arew] tr. Estienne’s World of Wonders 266
  He played with a little boy at titter-totter.

See-saw is also a reduplicative word, and its earliest citations are also from the 1600s, although a bit later than the previous one. However, those are all just interjections. The first noun use is this one:

• 1704 Swift Mechan. Operat. Spirit Misc. 297
  Then, as they sit, they are in a perpetual Motion of See-saw.

And the first verb citation is this:

• 1712 Arbuthnot John Bull ɪᴠ. vii,
  So they went see-sawing up and down, from one End of the Room to the other.