Hi,
My dictionary lists the following words as all meaning: necessity; need; requirement
必用、ひつよう
必要、ひつよう
要り用、いりよう
入り用、いりよう
Do these all really mean the same thing? If so, is one word used more than the others?
Thanks
The first two are variant spellings of the same word. Use 必要.
The second two are also more than one character associated with the same reading. 入り用is most common, but in fact fairly (very?) infrequently occurring.