与国 is read as よこく (yokoku) and means ally.
よこく
yokoku
よなぐにさん
atlas moth (Attacus atlas)
あたえる
to assign
あたえ
gift
よしんぎょうむ
credit business
あたえぬし
giver
よてん
point given
よけん
postulate
よのじゅう
fourth jūbako tray
よしん
credit
あずかりしる
to be aware of
よしき
the assigned equation
よかく
dative case