Hottest.
Yes, the word hottest is the superlative form for the adjective hot (hotter, hottest).
The word "hottest" is a superlative form of the adjective "hot." It functions as an adjective itself, describing the noun it modifies.
Hottest.
hottest
hottest
Yes - coldest, cold, cool warm, hot, hottest.
The comparative form of hot is "hotter". The superlative form is "hottest".
the iron becomes hottest because it is a conductor of heat
anthracite coal
hotter, hottest
hotter, hottest