at arm's length
 一臂之遙;保持相當距離;敬而遠之


 Length n.
 1. The longest, or longer, dimension of any object, in distinction from breadth or width; extent of anything from end to end; the longest line which can be drawn through a body, parallel to its sides; as, the length of a church, or of a ship; the length of a rope or line.
 2. A portion of space or of time considered as measured by its length; -- often in the plural.
    Large lengths of seas and shores.   --Shak.
    The future but a length behind the past.   --Dryden.
 3. The quality or state of being long, in space or time; extent; duration; as, some sea birds are remarkable for the length of their wings; he was tired by the length of the sermon, and the length of his walk.
 4. A single piece or subdivision of a series, or of a number of long pieces which may be connected together; as, a length of pipe; a length of fence.
 5. Detail or amplification; unfolding; continuance as, to pursue a subject to a great length.
 May Heaven, great monarch, still augment your bliss
 With length of days, and every day like this.   --Dryden.
 6. Distance. [Obs.]
    He had marched to the length of Exeter.   --Clarendon.
 At length. (a) At or in the full extent; without abbreviation; as, let the name be inserted at length. (b) At the end or conclusion; after a long period. See Syn. of At last, under Last.
 At arm's length. See under Arm.


 at arm's length
      adv : at some distance; "keep someone at arm's length"