Chino - traditional British officer's pant. These are your average slacks: think Dockers. Otherwise referred to as "khakis," since those are the most common color, arguably.
Khaki - see above.
Pleated - meaning the pants have small pleats (perhaps best equivocated to purposefully made creases in the fabric) in the front. There are usually two of these on either side.
Dress Pants - these you would usually wear with suits, they will probably be dark or pinstriped in color, probably made of wool in either Navy, Grey, or Black
Hint: go shopping at either J. Crew or Banana Republic and you should be set.