Originating in English in the early 16th century, inkling derives from Middle English yngkiling, meaning "whisper or mention," and perhaps further from the verb inclen, meaning "to hint at." It also shares a distant relationship with the Old English noun inca, meaning "suspicion." An early sense of the word meant "a faint perceptible sound or undertone" or "rumor," but now people usually use the word to refer to a tiny bit of knowledge or information that a person receives about something. One related word you might not have heard of is the verb inkle, a back-formation of inkling that occurs in some British English dialects and means "to have an idea or notion of."