Can "diligence" be used as a verb?

Solution 1:

I've never met this usage before and also the article (I post below) appears to show its rare usages as a curiosity. I don't recommend that you use it. "Do, perform (due) diligence" are more common usages.

• Diligencing. Do you like it? It is surely more elegant than the clunky “doing due diligence”, a corruption of “exercising due diligence”. “Diligencing” has already made a few appearances. In November last year, the FT reported Tony Lomas of PwC, administrators to Lehman Brothers in Europe, saying: “We’re still diligencing.”

• The first use I can find is in 2005 in the New York Observer, where lawyer Barry Ostrager complimented Chambers, the lawyers guide. “They’ve obviously gone to the trouble of not only diligencing the people who they include but distilling the commentary that they’ve received into some narrative form,” he said.

• Does “diligencing” have a history? “Doing diligence” does. Geoffrey Chaucer, advising on that age-old problem of unfriending, wrote: “Whan thou hast for-goon thy freend, do diligence to gete another freend.”

• “To diligence” does not seem to have appeared as a verb before, but its relation “to diligent” has. In The Byrth of Mankynde, a book about midwifery, the 16th-century writer Thomas Raynalde said: “Be [the earth] neuer so well diligented and picked, yet always therein will remaine seeds of vnlooked for weeds” – which describes the whole diligencing business pretty accurately.

(ft.com)