| Abandon | verb | ละทิ้ง | The broken car was abandoned on the side of the road. |
| Abstract | adj. | นามธรรม | Abstract concepts like love and freedom are hard to define. |
| Abundant | adj. | มากมาย | The island has abundant natural resources. |
| Academic | adj. | ทางวิชาการ | She has an outstanding academic record. |
| Accelerate | verb | เร่งความเร็ว | The car accelerated as it entered the highway. |
| Access | n/v. | เข้าถึง | We have easy access to the information online. |
| Accommodate | verb | อำนวยความสะดวก | The hotel can accommodate up to 500 guests. |
| Accompany | verb | ไปเป็นเพื่อน/ประกอบกับ | He accompanied her to the station. |
| Accumulate | verb | สะสม | Dust began to accumulate on the old books. |
| Accurate | adj. | แม่นยำ | The map was accurate and easy to follow. |
| Achieve | verb | บรรลุ | She worked hard to achieve her goals. |
| Acknowledge | verb | ยอมรับ | He acknowledged that he made a mistake. |
| Acquire | verb | ได้รับมา | The museum acquired a new painting. |
| Adapt | verb | ปรับตัว | Animals must adapt to their environment. |
| Adequate | adj. | เพียงพอ | The food supply was adequate for the trip. |
| Adjacent | adj. | ติดกัน | The library is adjacent to the science building. |
| Adjust | verb | ปรับเปลี่ยน | You can adjust the height of the chair. |
| Administer | verb | บริหาร/จัดการ | The project was administered by the university. |
| Administration | noun | การบริหาร/การจัดการ | The new administration announced plans to reform the tax system. |
| Adolescent | noun | วัยรุ่น | Adolescents often face many challenges. |
| Adult | noun/adj. | ผู้ใหญ่/โตเต็มวัย | The museum offers discounted tickets for children, but adults must pay full price. |
| Adopt | verb | รับเลี้ยง/นำมาใช้ | They decided to adopt a child. |
| Advocate | verb | สนับสนุน | They advocate for better education systems. |
| Aesthetic | adj. | สวยงาม | The building has a great aesthetic appeal. |
| Affect | verb | ส่งผลกระทบ | The rain will affect our plans. |
| Aggregate | verb | รวบรวม | The website aggregates news from sources. |
| Albeit | conj. | แม้ว่า | He was making progress, albeit slowly. |
| Allocate | verb | จัดสรร | The government allocated funds. |
| Alter | verb | เปลี่ยน | We had to alter our plans due to the rain. |
| Alternative | n/adj. | ทางเลือก | Do you have an alternative suggestion? |