| abstruse | Difficult to understand; obscure | |
| abstemious | Indulging only very moderately in something, especially food and drink | |
| absolute | Not qualified or diminished in any way; total | |
| abscission | The natural detachment of parts of a plant, typically dead leaves and ripe fruit | |
| abridge | To shorten (a book, movie, speech, or other text) without losing the sense | |
| abrasive | Showing little concern for the feelings of others; harsh | |
| abound | To be present in large numbers or in great quantity | |
| abort | To terminate (a process or an activity) prematurely | |
| aboriginal | Inhabiting or existing in a land from the earliest times or from before the arrival of colonists; indigenous. | |
| abnegate | To renounce or reject something desired or valuable | |