| acoustic |
having to do with sound or hearing. |
| costly |
having a high price or value. |
| deserve |
to be worthy of or have a right to. |
| geography |
the physical features of an area on the earth's surface. |
| lighten1 |
to become brighter or less dark in color. |
| longtime |
having existed or continued over a long period of time. |
| lumber1 |
logs cut into boards or beams for use in building. |
| necessary |
needed; essential. |
| noble |
belonging to a class of people with a high rank or title. |
| pollution |
poisons, wastes, or other materials that pollute. |
| rare1 |
not often found or seen; not common. |
| signal |
a movement, action, or device used to communicate instructions, warning, or other information. |
| tremble |
to shake from fear, weakness, or cold. |
| trigger |
to cause, begin, or set off. |
| waddle |
to walk using short steps while rocking from side to side. |