The Collaborative International Dictionary
goo-goo \goo"-goo\, n. same as goody-goody, n.. [Colloq. & disparaging]
goody-goody \good"y-good"y\, n. A person who is weakly, sentimentally, or affectedly good; a goody-goody person; -- sometimes used to refer to person who acts with good intentions but who bunglingly does more harm than good. The latter may sometimes be deprecatingly referred to as a goo-goo. [Colloq.]
Douglas Harper's Etymology Dictionary
"amorous," 1900, perhaps connected with goggle, because the earliest reference is in goo-goo eyes. The sense of "baby-talk" is from 1863. Use in reference to politics began 1890s, and seems to be a shortening of Good Government as a movement to clean up municipal corruption in Boston, New York, etc. It soon was extended to mean "naive political reformer."
Wiktionary
Etymology 1 n. (context derogatory English) A Philippine person. Etymology 2
n. (context US politics pejorative English) A government reformer
Usage examples of "goo-goo".
Danny was grateful she wasn't around to make goo-goo eyes and poke his biceps, copping feels while the watch sergeant chuckled.
I mean, I had the Acnes, who had a big, fat bullet: "I'll Be a Goo-goo for You.
The duke he never let on he suspicioned what was up, but just went a goo-gooing around, happy and satisfied, like a jug that's googling out buttermilk.