Egg-shaped container found in empty office (5)
I believe the answer is:
ovate
'egg-shaped' is the definition.
(I know that egg-shaped can be written as ovate)
'container found in empty office' is the wordplay.
'container' becomes 'vat' (vat is a kind of container).
'found in' indicates putting letters inside.
'empty' suggests removing the centre.
'office' with its centre removed is 'oe'.
'vat' inserted inside 'oe' is 'OVATE'.
(Other definitions for ovate that I've seen before include "philosopher" , "Shaped like an egg" , "Egg-shaped; Welsh bard" , "Egg-shaped, oval" , "Like Humpty Dumpty" .)