ADJECTIVE (3)

1. without fixed limits or restrictions;
- Example: "an open-ended discussion"

2. allowing for a spontaneous response;
- Example: "an open-ended question"

3. allowing for future changes or revisions;
- Example: "open-ended agreements"

The Collaborative International Dictionary of English v.0.48:

open-ended \open-ended\ adj.
   1. allowing for a spontaneous response; as, an open-ended
      question. Contrasted to multiple-choice.
      [WordNet 1.5]

   2. without fixed limits or restrictions, as to tpoic or time;
      as, an open-ended discussion.
      [WordNet 1.5]

   3. allowing for future changes or revisions; as, open-ended
      agreements.
      [WordNet 1.5]

WordNet (r) 3.0 (2006):

open-ended
    adj 1: without fixed limits or restrictions; "an open-ended
           discussion"
    2: allowing for a spontaneous response; "an open-ended question"
    3: allowing for future changes or revisions; "open-ended
       agreements"