a thing, reason, event etc that is unknown
entity
Cases of word usage
1) to think of something with hatred or disgust (abhor)
2) the capacity, skill or power needed to do something physical or mental (ability)
3) the act of abolishing something or being abolished (abolition)
4) to have a great number of quantity of something (abound)
5) in agreement with something (accordance)
6) to cause something to become greater in number or quantity (accumulate)
7) (an instance of) the process of collecting something (accumulation)
8) to say that (a person) has done wrong, has broken the law, is to be blamed (for something wrong) (accuse)
9) to show, make known, something; learn about something (acquaint)
10) to agree, accept, something without argument (acquiesce)