John Denver’s Ballad of Spiro Agnew. IIRC has 12.
“Lollipop”
Pink Floyd - Careful with that Ax Eugene
… 1… 2…
5 words!
6 if you include “arrrghghhh”
David Bowie by Phish
First verse: David Bowie (repeated)
Second verse: UB40 (repeated)
Oh, and TBWombat made me think of Monty Python’s Spam Song
Spam spam spam spam
Spam spam spam spam
Spam spam spam spam
Spam spam spam spam
Sorry, TPWombat! I hate mangling a moniker.
Badger badger badger badger MUSHROOM MUSHROOM
Tequila !!! by the Champs
Wow - I thought that would be one of the first mentioned. Granted, it’s an instrumental but since “Wipeout” was listed, Tequila must be acceptable too.
From the OP’s quoting of Little Nemo:
You woulda thought right, wolf 
Daniel
Even Oye Como Va only has 8 words:
“Oye como va/mi ritmo/bueno pagozar/mulata”
“Pick up the pieces”-Average White Band
Van McCoy’s “The Hustle.”
Besides which, there are more lyrics to the song than just that one line.
“I’m So Glad” by Cream
DanielWithrow
I thought I was being extra careful by doing an Edit/FInd search through the entire page and came up with nothing. Who would have thought that I should have been searching for “t*q**la” !!! Sheesh !!!
Napalm Death’s “You Suffer” has just two words in the lyrics and they aren’t repeated.
The Beatles were mentioned, but not “You Know My Name (Look Up The Number)”?
Huey Lewis and the News also did a song called “Slammin’”, which consists of only one word once, the title.
If I counted correctly, “Flashlight” by Parliament has only 20 words. Is this over the limit for this thread?
“A Huevo”, by Los Straitjackets
Silly song back in the 70s(?) that the Muppets actually covered
Ma Na Ma Na
Ma Na Ma Na
Ma Na Ma Na
…