since 有因为的意思吗

有。在牛津字典里的解释及例句：
because; as 因为; 既然; 由於: Since we've no money we can't buy a new car. 因为我们没钱, 没法买新汽车.

since“自从”，也有“因为”的意思。
Young students are advised not to eat too much food ,since it's bad for their health.
建议年轻的学生不要吃太多食物，因为那样对健康有害。

有