RALPH: The original meaning of the word pregnant was the same as its common meaning today, deriving from the latin words pre — meaning before, and genesis — meaning birth.

SARAH: But Shakespeare almost always uses pregnant and unpregnant in a figurative sense. When Polonius comments how pregnant some of Hamlet's replies are, he means that they are full of hidden meaning, just as a pregnant woman is "full" of an infant to be born, who is nevertheless hidden from sight.

RALPH: Later on, in Act III, Hamlet will be making fun of flatterers, or brown-nosers, who bend the pregnant hinges of their knees. The pregnant hinges of their knees means the knees are ready and waiting to bend or kneel down — meaning that these people only too willing kneel down obsequiously to the person they're flattering. We'll see Hamlet use the word "unpregnant" in his monologue at the very end of Act II, scene 2, which we'll also look at together.