Collins Chinese Dictionary Plus (3rd edition), 2011:
since [sɪns]
I adv
1
(=from then onwards) 此后(後) cǐhòu
- They went to college together and have done business together since.
他们(們)一起上的大学(學)并(並)从(從)此后(後)一起做生意。 Tāmen yīqǐ shàng de dàxué bìng cóng cǐ hòu yīqǐ zuò shēngyì.
2
(=latterly) 后(後)来(來) hòulái
- 6,000 people were arrested, several hundred of whom have since been released.
6000人被逮捕，其中几(幾)百人后(後)来(來)被释(釋)放。 Liùqiān rén bèi dàibǔ，qízhōng jǐ bǎi rén hòulái bèi shìfàng.
II prep
1
(=from) 自…以来(來) zì…yǐlái
2
(=after) 从(從)…以后(後) cóng…yǐhòu
- I haven't seen powdered eggs since the war.
自战(戰)后(後)我从(從)未见(見)过(過)鸡(雞)蛋粉。 Zì zhàn hòu wǒ cóng wèi jiànguò jīdànfěn.
III conj
1
(=from when) 自从(從) zìcóng
- I've been wearing glasses since I was three.
我从(從)3岁(歲)起就戴眼镜(鏡)。 Wǒ cóng sān suì qǐ jiù dài yǎnjìng.
2
(=after) 从(從)…以后(後) cóng…yǐhòu
- So much has changed in the sport since I was a teenager.
自我十几岁起，这项运动已经改变了很多。 Zì wǒ shí jǐ suì qǐ, zhè xiàng yùndòng yǐjīng gǎibiànle hěnduō.
3
(=as) 因为(為) yīnwèi
- since then or ever since
从(從)那时(時)起 cóng nàshí qǐ - I've been here since the end of June
我自6月底以来(來)一直在这(這)儿(兒)。 wǒ zì liùyuè dǐ yǐlái yīzhí zài zhèr - since it was Saturday, he stayed in bed an extra hour
因为(為)是星期六，他在床上多呆了一小时(時)。 yīnwèi shì xīngqīliù,tā zài chuáng shang duō dāile yī xiǎoshí - long since
很久以前 hěn jiǔ yǐqián
for 用来表示过去、现在或将来某事持续的时间的长短，或未发生某事的时间的长短。She slept for eight hours…He will be away for three weeks…I hadn't seen him for four years. 表示某个时间段开始时，用 since 。She has been with the group since it began…the first civilian president since the coup 17 years ago… since 还可以表示某事发生的最后时间，或者未发生某事的时间的长短。She hadn't eaten since breakfast…It was a long time since she had been to church.