What's the word for "to have a quality, idea or emotion faintly"?

Solution 1:

I like whiff, because you get that instant visual of somebody with their nostrils flaring.

Some dictionaries don't have it, but MW has one definition as "...slight trace or indication...", so, you could use it in that sense.

Solution 2:

@Jason Bassford has made good suggestions, IMO (hint, and trace).

You could also use phraseology like "to have a soupcon of"

soup·çon *[so͞opˈsoN] NOUN - a very small quantity of something

"The board's final report had a soupcon of concern over the adverse combination of new business competitors and increased manufacturing costs and the potential this might have on projected earnings. Overall though, the health of the company is very stable and business is proceeding as per usual."

You could also try more abstract approaches like:

• "X has elements of Y," or even
• "A has touches of B"