cone phoneticPhoneticPhoneticPhoneticPhoneticPhoneticPhonetic PhoneticPhoneticPhoneticPhoneticPhoneticphonetic noun [C] 
a solid shape with a round or oval base which narrows to a point, or any of various objects shaped like this, some of which are hollow and open at the end 
I ate the ice-cream but threw away the cone.
The police have sectioned off part of the road with traffic cones.

A cone is also the hard oval shaped fruit of a conifer one of various types of evergreen tree . 

cone off phoneticPhoneticPhoneticPhoneticPhoneticPhoneticPhonetic PhoneticPhoneticPhoneticPhoneticPhoneticphonetic phrasal verb [T] 
Part of the road had been coned off for repair work.

conical phoneticPhoneticPhoneticPhoneticPhoneticPhoneticPhoneticPhoneticPhoneticPhoneticPhoneticPhoneticPhonetic PhoneticPhoneticPhoneticPhoneticPhoneticPhoneticPhoneticPhoneticPhoneticphonetic adjective 
An object which is conical is shaped like a cone. 
a conical flask
( Cambridge International Dictionary of English )