totter v.

"to shake, tremble," 1610s, perhaps a variant of dadder, from Middle English daderen "to quake, tremble" (mid-14c.) a frequentative formation on a pattern similar to totter, patter, etc. Wedgwood points to a large group of similar words signifying motion to and fro, including dither, diddle, dandle, toddle, doddle ("shake the head," 1650s). Related: Doddered; doddering.

1843, "to seesaw," alteration of Middle English titter "move unsteadily," probably from a Scandinavian source akin to Old Norse titra "to shake, shiver, totter, tremble," from Proto-Germanic *ti-tra- (source also of German zittern "to tremble"). Meaning "move unsteadily, be on the edge of imbalance" is from 1844.

Noun teeter-totter "see-saw" is attested from 1871 (earlier simply teeter, 1855, and titter-totter in same sense is from 1520s). Totter (n.) "board swing" is recorded from late 14c.; see totter (v.), and compare see-saw.