adjective

• Easy to use.
• Suitable; competent.
• Liable to.
• Having the necessary powers or the needed resources to accomplish a task.
• Free from constraints preventing completion of task; permitted to; not prevented from.
• Having the physical strength; robust; healthy.
• Rich; well-to-do.
• Gifted with skill, intelligence, knowledge, or competence.
• Legally qualified or competent.
• Capable of performing all the requisite duties; as an able seaman.

verb

• To make ready.
• To make capable; to enable.
• To dress.
• To give power to; to reinforce; to confirm.
• To vouch for; to guarantee.

noun

• The letter "A" in Navy Phonetic Alphabet.