www.alphadictionary.com

Inkling (noun)

1. A slight hint, clue, indication or suggestion.
2. A slight knowledge or understanding, or vague idea.

Examples:
"Reading the summary will give you an inkling of what the book is about."
"They had no inkling of the dangers involved in crossing the ocean."

From Middle English inclen, "to hint", "to utter in an undertone".

According to the American Heritage Dictionary, however, it probably comes from Middle English ningkiling or nikking, from nik, "notch, tally", perhaps related to French niche.

Great word, but it seems to me that the AHD is way off the mark. I don't get the association of the derivation to the current meaning.

Interestingly, inkling, though meaning a hint of something, has no connection with a stage cue.

Wasn't it at Cambridge that CS Lewis gathered a coffeeKlatch (teaKlatch) discussion group they named the Inklings?

Oxford, C S Lewis with Tolkien, amongst others.

http://en.wikipedia.org/wiki/Inklings