Translation:I am not young.
We call it "negation", but, yes, I think you have the concept. Note that it only works for negation when attached to a verb.
There is also a noun be' which means "female, woman" and appears at the end of many nouns to indicate it is the female version of that thing (such as puqbe' for "girl"). Note that these two syllables are unrelated and Klingons respect women regardless of this coincidence.