The transition can be as below:
So can I just add the letter "y" after ANY noun to creat a new word that is meaningful?
If somebody looks like a leader, can I say he is leadery?
Or if something looks like a cat, can I say it's caty?
Thank you very much~~
The short answer is no you can't; 'catty' with two 't's' exists but it doesn't mean 'catlike'.