根際 is read as ねき (neki) and means (one's) side.
ねき
neki
こんぼん
foundation
ねまわし
digging around the roots of a tree (before transplanting)
ね
(fishing) reef
こんじょう
character
ねっこ
root (of a plant)
こんき
patience
ねざす
to come from
こんじ
complete cure
ねづよい
firmly rooted
こんぽんてき
fundamental
こんてい
root
こんぜつ
eradication