Source : Webster's Revised Unabridged Dictionary (1913)

Speculative \Spec"u*la*tive\, a. [Cf. F. sp['e]culatif, L.
   speculativus.]
   1. Given to speculation; contemplative.

            The mind of man being by nature speculative.
                                                  --Hooker.

   2. Involving, or formed by, speculation; ideal; theoretical;
      not established by demonstration. --Cudworth.

   3. Of or pertaining to vision; also, prying; inquisitive;
      curious. [R.] --Bacon.

   4. Of or pertaining to speculation in land, goods, shares,
      etc.; as, a speculative dealer or enterprise.

Source : WordNet®

speculative
     adj 1: not financially safe or secure; "a bad investment"; "high
            risk investments"; "anything that promises to pay too
            much can't help being risky"; "speculative business
            enterprises" [syn: {bad}, {insecure}, {risky}, {high-risk}]
     2: not based on fact or investigation; "a notional figure of
        cost helps in determining production costs"; "speculative
        knowledge" [syn: {notional}]
     3: showing curiosity; "if someone saw a man climbing a light
        post they might get inquisitive"; "raised a speculative
        eyebrow" [syn: {inquisitive}, {questioning}, {wondering(a)}]