This Doctor Who screencap contains
business suit.
There might also be
dress suit, full dress, tailcoat, tail coat, tails, white tie, white tie and tails, suit, suit of clothes, and concert.
This are the scenes from the episode from season 4 "Partners in Crime" that included Howard Attfield (Geoff Noble). Sadly Howard died shortly after and was replaced by Donna's uncle Bernard Cribbins (Wilf Mott).