固守 is read as こしゅ (koshu) and means clinging.
こしゅ
koshu
しゅびがため
making replacements for defensive purposes in the late inning of a game
こてい
fixation (histology)
こゆう
characteristic
こたい
solid (body)
かためる
to hold a bow fully drawn
こけい
かたまる
to become firm
こていしさん
fixed assets
かため
somewhat hard
こていひ
fixed cost
こていかんねん
fixed idea
こか
solidification