It is difficult to give an exact translation of this term, but I'll try my best. This word is used mainly in literary texts, nursery rhymes and folk songs to express a motion of something (most frequently a soft plant stem) that is moving gently, gracefully back and forth, swaying, wobbling (e.g. in the wind). This is one of those onomatopoeic words in Hungarian which consist of two parts. The first part comes from "inog", that is, to sway/swing. The second part has no meaning, it just imitates the first one, thus adding to the playfulness of the expression and setting the mood. I hope this helps to understand it better.