| Absolutely necessary |
ESSENTIAL |
| Accomplishing an objective, efficient |
EFFECTIVE |
| Air travel |
AVIATION |
| Aircraft and smoothing tools |
PLANES |
| Became aware of |
REALISED |
| Black-and-white diving bird |
AUK |
| Bold and daring |
AUDACIOUS |
| Boundaries, demarcation lines |
LIMITS |
| Brings water to 100 degrees Celsius |
BOILS |
| Devising, designing |
PLANNING |
| Difficulties to be resolved |
PROBLEMS |
| Division of geological time |
ERA |
| Drowsy |
SLEEPY |
| Fashions or distinctive modes |
STYLES |
| Felt hats with creased crowns |
HOMBURGS |
| Fidgety, uneasy |
RESTLESS |
| French title |
MONSIEUR |
| Fundamental |
BASIC |