Correct me if I'm wrong:
What behaviourists attempt to do as far as meaning is concerned (and as opposed to psychoanalysts), they strive to identify meaningful from meaningless statements through verification in praxis. For example, 'dragons exist' (to go back to our previous thread) is not so much false (or true for that matter, depending on context) as it is meaningless. Why? There is no way of verifying or falsifying the statement through empirical (use of the senses) means. But this very principle breaks down due to its own incohrence; it cannot be verified or falsified by empirical means either! Hence, it itself is meaningless. Freud, on the other hand, would be introspective and probably claim that the meaning of the sentence 'dragons exist' be approached based on impulses buried in an uncanny, hypothesised subconscious. This makes him (at least in the beahaviourisis' eyes, who don't even believe in the existence of a subconscious or ego as such) highly subjective.
Although "Darwinian" in their outlook, some behaviourists (Skinner) stress the importance of subjectivity in the creation of personality theories. In a way, behaviourism has opened up to psychoanalytical ideas that once would have been anathema. It cannot explain meaning with a scientific, objective outlook only, or reduce meaning to behaviour.