Does "candlelight" mean "compare side by side"?

Solution 1:

I'm going to go ahead an put in an official answer to the actual question.

"Is it a recognised use of the word?"

The simple answer is, very strongly,

"No."

your friends / fellow inmates / bosses are either

(i) using a very strange "inside" terminology - perhaps from some specific technical field

(ii) using an "inside joke" -- some linguistic quirk that has built up between them.

(iii) they are using a confused - essentially "wrong", "silly" - mishearing or similar mistake.

A vast number of highly intelligent / professionally linguistic / literate people are on this 'ere list; and nobody's cottoned-on to anything.

So honestly, the answer to your specific question is "No"

I can confidently speak for the entire mailing list, when I say, we'd love some feedback on just what they meant. Cheers!

Solution 2:

Note that candlestick charting is a technical term used in talking about stock markets.

Is there a chance this is the term you overheard?

(To be clear, the actual image you present looks nothing like a candlestick chart in any way. But there may have been some confusion.)

Candle as a verb can refer to examining eggs by holding in front of a candle.

It's very vague, but this makes me think of when you hold something up to a lightsource like this ...

Conceivably, your colleagues have in mind something related to: holding one up to the other with a light source behind.

But it's totally confused, and not in any way an idiom or anything that makes sense. Almost certainly, it is simply a mishearing somewhere along the chain.

Solution 3:

I have not come across this usage. My guess is that it is derived from the practise of candling eggs to check for development of the embryo. http://en.wikipedia.org/wiki/Candling