I'm trying out a new definition style for my thesis. If a new term is introduced, I repeat it in the margin (and emphasize it inline). A simplified demonstration:
\newcommand*{\idef}[1]{%
\marginnote{\fbox{#1}}%
\emph{#1}%
}
Sometimes, two new terms will be introduced on the same line. Right now the second margin-note will just overlap the first. I'd like it placed next to the first. Or below the first, in the absence of horizontal space.
How could I accomplish this?
Edit: All solutions proposed so far (including my own) can only place excess notes below others. Ideally, when there's space, I'd like a same-line-origin note to be placed next to the previous (to its right).
This is tricky, depending on when \marginpars are typeset, exactly. I believe the only way would be to postpone typesetting the note until the end of the line has been reached, and 'prepare it' until then. But I'm a bit out of my element there.

\marginpar. – egreg Dec 27 '12 at 21:05\marginparoften gives me bad placement (right margin on even page for example). I've had more predictable and robust results with\marginnote. – mhelvens Dec 27 '12 at 21:08mparhackpackage. With\marginnoteyou don't have the feature you'd like. Are those margin notes to appear also in the final version? I hope not. – egreg Dec 27 '12 at 21:46mpnotepackage http://tex.stackexchange.com/questions/78193/margin-notes-with-a-pointing-arrow-that-are-automatically-vertically-adjusted – David Carlisle Dec 28 '12 at 00:51