Sentence:  On this , she builds an `` <WSD>egg</WSD> compartment '' or `` egg cell '' which is filled with that famous pollen and nectar mixture called beebread . 
Meaning of the word marked with <WSD> tags:  animal reproductive body consisting of an ovum or embryo together with nutritive and protective envelopes; especially the thin-shelled reproductive body laid by e.g. female birds