形容詞 loyal:

1. steadfast in allegiance or duty
2. inspired by love for your country
   同義詞：patriotic
3. unwavering in devotion to friend or vow or cause
   同義詞：firm, truehearted, fast

1. We are loyal to our motherland.
   我們忠于祖國。
2. He remained loyal to me through thick and thin.
   他歷盡艱辛始終都忠實於我。
3. Qualify your statement that "dog is loyal" by adding "usually".
   將你說的＂狗是忠誠的＂這句話修正一下，加上＂通常＂二字。
4. The vassal swore that he would be loyal to the king forever.
   這位封臣宣誓他將永遠忠誠于國王。
5. I may say in all sincerity that you have been my most loyal friend.
   我可以非常真誠地說，你一直是我最忠實的朋友。
6. The soldiers are loyal to their country.
   士兵們忠于他們的國家。

loy.al

adj.（形容詞）
Steadfast in allegiance to one`s homeland, government, or sovereign.
忠心的：對自己的祖國，政府或主權(quán)無限忠誠的
Faithful to a person, an ideal, a custom, a cause, or a duty.
忠誠的：對一個人。一種理想，習慣，事業(yè)，責任忠實的
Of, relating to, or marked by loyalty.See Synonyms at faithful
忠誠的：與之有關(guān)的，或有其特征的參見 faithful

來源：
French
法語
from Old French leial, loial
源自 古法語 leial, loial
from Latin lôg3lis [legal]
源自 拉丁語 lôg3lis [合法的]
from lôx lôg- [law] * see leg-
源自 lôx lôg- [法律] *參見 leg-

【引伸】
loy.ally
adv.（副詞）