essentiality

Yes.
1. 必要性; 根本性; 實質性
2. 要素; 本質
變化:
名詞複數：essentialities

辨析:
同義參見:
necessity
requirement

HOPE I CAN HELP YOU ^_^

Does the word 'essentiality' exist? if yes, what does it mean?

n. 名詞

1.必要性；根本性；實質性
2.要素；本質

Does the word 'essentiality' exist ?
Yes

Essentiality (noun)
1. the quality of being essential; essential character. 必要性；根本性；實質性
2. an essential feature, element, or point.要素；本質

Examples:
"For metabolite essentiality, each metabolite was removed one by one." ~ from Nature
“No one questions the validity, the urgency, the essentiality of the Voting Rights Act,” he added. ~ from New York Times

這個字很專門, 很多時在 scientific journals 見過,
I don't recommend using this word if you can help it, especially in Hong Kong school exam.不是常見常用字

Oxford Advanced Learner's Dictionary, Longman, Cambridge, Macmillan, Collins Cobuild, Chambers
上述的英國字典沒有
Oxford English Dictionary, Collins English Dictionary 只僅僅提到

但是出現在美國字典, Yahoo, Free Dictionary, Dictionary.com, Merriam Webster, Encarta, Random House

I guess that 回答者：yip****** most likely uses a British Dictionary.

yip******, get a better dictionary for reference before attempting to give an answer. Your wrong answers cause more harm than good!

2015-01-02 07:23:40 補充：
Please refer to the explanation in Godfrey's answer about yip******'s mistake (not the "Star answer of the week").

2015-01-02 07:34:42 補充：
yip*******, a good online dictionary web for you to use is http://www.thefreedictionary.com/ which includes English and American dictionaries.

1. Yes.

2. See here:

http://www.merriam-webster.com/dictionary/essentiality

Does the word 'essentiality exist ?
Answer: No, it is not, but you can use 'essential' instead; as its meaning is indispensable element. 要素;要點

essentiality 查有此字，解必要的，必須的。

2015-01-01 14:45:20 補充：
if i did, give yours, i won't challenging you!