| obsolete |
| 1. adj. (of words, equipment, etc.) No longer in use; gone into disuse; disused or neglected (often by preference for something newer, which replaces the subject). | |
| It is speculated that, within a few years, the Internet's speedy delivery of news worldwide will make newspapers obsolete. | |
| 2. adj. (biology) Imperfectly developed; not very distinct. | |
| 3. v. (transitive, US) To cause to become obsolete. | |
| This software component has been obsoleted. | |
| We are in the process of obsoleting this product. | |
| troublesome |
| 1. adj. Causing trouble or anxiety | |
| The computer has been very troublesome for me. It never works when I need to use it. | |
| vexatious |
| 1. adj. Causing vexation or annoyance; teasing; troublesome. | |
| 2. adj. (archaic) Full of trouble or disquiet | |
| 3. adj. (legal, of an action) Commenced for the purpose of giving trouble, without due cause. | |
| a vexatious lawsuit | |
| 4. adj. (legal, of a party or entity) In the habit of starting vexatious litigation and therefore liable to have restraints placed on one's ability to access the courts. | |
| a vexatious litigant | |
| persistent |
| 1. adj. Obstinately refusing to give up or let go. | |
| She has had a persistent cough for weeks. | |
| 2. adj. Insistently repetitive. | |
| There was a persistent knocking on the door. | |
| 3. adj. Indefinitely continuous. | |
| There have been persistent rumours for years. | |
| 4. adj. (botany) Lasting past maturity without falling off. | |
| Pine cones have persistent scales. | |
| 5. adj. (computing) Of data or a data structure: not transient or temporary, but remaining in existence after the termination of the program that creates it. | |
| Once written to a disk file, the data becomes persistent: it will still be there tomorrow when we run the next program. | |
| 6. adj. (mathematics) Describing a fractal process that has a positive Brown function | |
| 7. adj. (mathematics, stochastic processes, of a state) non-transient. | |
