Sentence:  to <WSD>pack</WSD> a trunk;  the play, or the audience, <WSD>packs</WSD> the theater 
Meaning of the word marked with <WSD> tags:  To fill in the manner of a pack, that is, compactly and securely, as for transportation; hence, to fill closely or to repletion; to stow away within; to cause to be full; to crowd into.