I need help with Economic terms...

Oh what is the difference between next words…

Economy -
Economics -
Economise -
Economic -
Economical -
Economically -
Economist -

I think I can make a difference between few terms,but not all… and how should I spell word Economise?

You can get the answers to all your questions in a dictionary.

In both US and UK English (if you believe the Oxford dictionaries), “economize” is the basic spelling, and “economise” is a variant.

I would spell it ‘economise’ because I’m British.
I would also spell these words with an ‘s’:
organise
prioritise
finalise

dictionary.reference.com/browse/-ize

Yep… it’s how it’s written in my book.
E’conomy
Eco’nomics
E’conomise
Eco’nomic
Eco’nomical
E’conomist
Eco’nomically
Because of accenting words…
’ - indicates the stressed syllable in this group of words.

I deliberately used a British dictionary to check the spelling of the word before I responded. The Shorter Oxford English Dictionary lists “economise” as a variant of “economize”. See also here:
oxforddictionaries.com/page/157

British spelling does not uniformly spell that suffix “-ise” on all words, and American spelling calls for “-ise” on many words (advise, advertise, etc.).

The fact that the European Union found it necessary to declare its own spelling rules, independent of the British, and proclaim that henceforth the suffix shall always be spelled “-ise”, shows that there are exceptions in UK English that the French were having problems with.