彻底 (chèdǐ)

Thorough or complete means going all the way through something without leaving any part unfinished, unexamined, or unchanged.

Meanings

[adjective] thorough; complete; radical; without reservation
[adverb] thoroughly; completely; to the bottom; utterly

Example Sentences

这次改革必须彻底，不能半途而废。 Zhè cì gǎigé bìxū chèdǐ, bù néng bàntú ér fèi. This reform must be thorough and cannot be left halfway done.

医生建议他彻底休息两周，不要工作。 Yīshēng jiànyì tā chèdǐ xiūxi liǎng zhōu, bùyào gōngzuò. The doctor advised him to rest completely for two weeks and not work.

警方彻底调查了这起事故，最终找到了真相。 Jǐngfāng chèdǐ diàochále zhè qǐ shìgù, zuìzhōng zhǎodàole zhēnxiàng. The police thoroughly investigated this accident and ultimately found the truth.

这次失败让他彻底改变了自己的学习方式。 Zhè cì shībài ràng tā chèdǐ gǎibiànle zìjǐ de xuéxí fāngshì. This failure made him completely change his study methods.

要彻底解决这个问题，需要从根本上改变现有制度。 Yào chèdǐ jiějué zhège wèntí, xūyào cóng gēnběn shàng gǎibiàn xiànyǒu zhìdù. To thoroughly solve this problem requires fundamentally changing the existing system.

他彻底放弃了原来的计划，开始重新规划未来。 Tā chèdǐ fàngqìle yuánlái de jìhuà, kāishǐ chóngxīn guīhuà wèilái. He completely abandoned the original plan and began to replan his future.

Collocations

Collocation	Meaning
彻底改变 (chèdǐ gǎibiàn)	to completely change
彻底解决 (chèdǐ jiějué)	to thoroughly resolve
彻底调查 (chèdǐ diàochá)	to thoroughly investigate
彻底失败 (chèdǐ shībài)	to completely fail
彻底改革 (chèdǐ gǎigé)	to thoroughly reform
彻底放弃 (chèdǐ fàngqì)	to completely give up

Usage Notes

彻底 can modify both adjectives and verbs. Before a verb: 彻底调查 (to thoroughly investigate). Before an adjective or as a predicate: 改革不够彻底 (the reform is not thorough enough). It conveys the idea of going all the way to the bottom (底 = bottom) and leaving nothing behind.

彻底 implies a clean, complete resolution rather than a partial one. It is often used in contexts where incomplete action would be ineffective or problematic, such as medical treatment, legal investigations, or systemic reforms.

Memory Hook

彻 (to penetrate/pass through) + 底 (bottom) -- piercing all the way through to the very bottom. Nothing is left unexamined or untouched.