English Most Important Opposite/Antonym Words List alive – dead all – none allow – forbid already – not yet always – never ancient – modern amateur – professional amuse – bore ancestor – descendant angel – devil animal – human annoy – satisfy answer – ask answer – question antonym – synonym apart – together argue – agree arrest – free arrival – departure arrive – depart artificial – natural ascent – descent ask – answer asleep – awake attack – defend attack – defence attic – cellar autumn – spring awake – asleep awful – nice back – in