Do “chorus” and “refrain” have different connotations?

According to Ken Stephenson in his What to Listen for in Rock: A Stylistic Analysis, a chorus is a complete section of a song that is repeated, where a refrain is a line or two (often at the end of each verse or the beginning of each chorus) that return throughout the song but don't constitute a separate formal division on their own.

Honestly, I thought that chorus was more about songs and refrain for poems and similar things.

But, as the OALD states, they're synonyms and they both mean "the part of a song or a poem that is repeated after each verse".

My experience as a musician of many years, and after attending a number of songwriter camps (which generally recognize current or contemporary usage of terms) taught by professional songwriters is this: A chorus is understood by most to be as identified in answers and comments above, i.e, a repeating and complete section of a song sung by more than one singer, which typically drives the song's theme and/or is a summation of the song's ideas or point. In industry parlance, it's the "hook". A refrain, however, has a bit more malleable definition. While it can be more or less synonymous with a chorus, it generally means one or two repeating "tag lines" after or between verses, or before a chorus. Some songs have no chorus, and thus the tag lines become the repeating theme or hook. A more modern usage describes a repeating refrain happening just before each chorus as a "pre-chorus", although technically this may be an inaccurate usage of either term.

So everyone's been trying to define chorus and refrain, but I hadn't seen anyone cite an example, so I'll stick my neck out on this one to see how far off or how close I/we are. The song example is "Day Tripper" by The Beatles. Here we go:

Intro: guitar lick, bass & rhythm guitar in, drums in. The song has started

Verse 1: "Gotta good reason...(you know the words. I'm not gonna write it all out!)

Chorus: "She was a Day Tripper...to find out...I found out"

Verse 2: "She's a big teaser..."

Chorus: "She was a Day Tripper..."

The next part I don't consider a bridge but more a "B" section when the song reaches the musical interlude (modulate to the 5, lead guitar "solo"). At the conclusion of section B, the song returns to the intro riff and on to verse 3.

Verse 3: "Try to please her..."

Chorus: "She was a Day Tripper..."

Refrain/outro: "Day Tripper...Day Tripper, yeah..."

And fade

Let me know what you musical scholars and rock nutz think. I'm writing out some cheapie charts for a Whispers song and I was wondering what to call some of the vocal parts.

Cheerio!