| Answer | Crossword Clue |
|---|---|
| surface | The upper limit of a body of liquid |
| surfaces | The upper limit of a body of liquid |
| ultrasonic | Of or involving sound waves with a frequency above the upper limit of human hearing |
| timberline | the upper limit of timber trees on a mountain |
| timberlines | TIMBERLINE, the upper limit of timber trees on a mountain |
| maxing | to reach an upper limit or a peak the car maxed out at 85 mph |
| maxed | to reach an upper limit or a peak the car maxed out at 85 mph |
