Napiform
A little-used but useful adjective meaning turnip-shaped.
Large and round at the top and tapering down sharply and becoming exceedingly slender toward the bottom tip.
'A napiform root is one when much swollen at the base, so as to become broader than long, as that of the turnip.' (The Complete Herbalist by Dr.
O.
Phelps Brown, 1878) The word napiform comes from the Latin napus (turnip) + the Latin forma (form)