Sorry, got my C&P mixed up! Here's what Lucian said:
46. French writer, still with regiment, put on a uniform (7)
Answer: Henry David THOREAU. This may very well not be correct, as this particular Hank was a Yank, not French. Still, here goes. My solution is THO (i.e. “still”, as in a shortened form of “though”) followed by RE (i.e. “regiment”, specifically the Royal Engineers), then A and finally U (i.e. “uniform” – not an abbreviation explicitly recognised in my Chambers, but is used in the initials UBR – Uniform Business Rate), like so: THO-RE-A-U. Yuck, in a word.
[EDIT: Lee comes to the rescue again in the comments, clarifying the U. Thanks, Lee! – LP]