I have the same issue on my site. I am getting truly creamed for widgets, but have achieved number one ranking for at least 7 other search terms that are nearly-widgets. To me, I can live with that as it seems that most of my competitors are fighting for widgets which, given that the topic is diverse and not well defined.
on-page stuff like meta title, description, & keyword, H Tag Titles, title attributes, & keyphrases in body text is better for 2, 3 or 4 word keyphrases. Off-page stuff "all anchors" pointing to... are better as singular words... where the relevancy is can be assisted on many different keyphrase.
e.g. - >> widgets << as link would relevant to any type of "widgets".
Diversifies to targeting many, many keyphrases plus the primary keyword rather than just one.