Reduplication.
Bric-a-brac, chit-chat,
dilly-dally, ding-dong,
fiddle-faddle, flimflam,
hippety-hoppety, kitcat,
knick-knack, ping-pong,
pitter-patter, riff-raff,
riprap, see-saw,
shilly-shally, sing-song,
teeny-tiny, mish-mash,
teeter-totter, tick-tock,
ticky-tacky, tip-top,
tittle-tattle, wish-wash,
wishy-washy, zig-zag.
Read it out loud.