► 名詞余分  [よぶん]    
meaning:  extra  rank: 2☆ 
一個余分だ ⇨ We have one more than we need, one too many
☆ 余分の
椅子を
少し
用意したほうが
良い ⇨ We should prepare, have, some extra chairs
► 形容動詞余分  [よぶん]    
meaning:  extra  rank: 2☆ 
御飯を余分に
炊いた ⇨ I cooked rice a little more than needed
More examples:- 念の為余分を用意することにした ⇨ I decided to prepare extra just to be safe
 - 一応余分を用意しておいた ⇨ I have prepared some extra to be safe