Definition of unable

Short definition: The word unable means not having the ability, chance, or power to do something at a certain time. People use it to explain personal limits, unexpected difficulties, or situations where things are simply not possible.

Looking for a clear and natural explanation of the word unable? The word unable is used when someone wants to say they cannot do something, not because they don’t want to, but because something truly stops them. It can be about physical limits, emotional struggles, lack of time, or situations that make an action impossible at the moment. In everyday life, unable often appears in honest explanations, polite refusals, and moments when people need to admit their limits. Below, each meaning is explained in a relaxed and natural way, with explanations that sound human instead of stiff like a textbook.

Form: unable (adjective)
Opposite: able adj.
Related: inability n., disable v.
Syllable: un-a-ble

1. Not having the ability to do something.

   In its most common meaning, unable describes a situation where a person simply does not have the power, skill, or condition needed to do something. It is often used when someone feels disappointed, because they want to do more but cannot.

   He was unable to lift the heavy box by himself, even though he really wanted to help.
   She felt sad being unable to attend the wedding, because she had already planned to be there for months.
   After the accident, he was unable to walk for several weeks, and had to learn patience for the first time in his life.

   Synonyms: not able, incapable, powerless, unable to manage, not capable, lacking ability, not in a position to, helpless, unable to do, without the power, restricted, limited
   Antonyms: able, capable, skilled, strong enough, empowered, competent, qualified, ready, fit to do, prepared, able-bodied, effective

2. Not being in a position to do something because of circumstances.

   Sometimes unable does not mean lacking ability, but facing a situation that makes action impossible. It can be about time, rules, distance, or responsibilities. In this sense, the word sounds polite and honest, often used in formal or careful communication.

   I’m unable to join the meeting tomorrow, because I already have an important appointment.
   She was unable to reply quickly, since she had no internet access during her trip.
   They were unable to accept the offer, not because they didn’t want to, but because the timing was wrong.

   Synonyms: not in a position to, cannot manage to, prevented from, not free to, blocked from, restricted from, unable due to, kept from, hindered, stopped from, held back, unable at the moment
   Antonyms: free to, able to, available for, ready to, allowed to, in a position to, capable of, open to, able right now, prepared to, permitted to, willing and able

3. Used politely to refuse or explain limits.

   Unable is often chosen when people want to sound respectful while saying no. It softens the message and shows that the refusal is about circumstances, not lack of care.

   Thank you for the invitation, but I’m unable to attend this time.
   He politely explained that he was unable to help, even though he truly wished he could.
   The manager said she was unable to approve the request, but promised to review it again later.

   Synonyms: cannot at this time, regretfully cannot, not able right now, sorry but cannot, unable to accept, unable to help, cannot manage, unable to commit, unable to proceed, cannot do so, not possible now, unable to take part
   Antonyms: happy to help, able to assist, glad to do, willing to help, ready to support, available to do, pleased to accept, able to proceed, ready to join, happy to attend, willing and able, free to help

4. Feeling emotionally or mentally stuck.

   Sometimes unable talks about inner struggles. A person may be physically capable, but emotionally not ready to act or decide. In this sense, the word shows vulnerability and honesty about personal limits.

   She was unable to speak about the loss, because the pain was still too fresh.
   He felt unable to make a decision, torn between what he wanted and what he feared.
   Sometimes people are unable to forgive, not because they don’t want peace, but because healing takes time.

   Synonyms: emotionally blocked, mentally stuck, not ready, unable inside, struggling to act, hesitant, overwhelmed, emotionally limited, mentally restrained, unable to cope, feeling trapped, unable to move forward
   Antonyms: emotionally ready, confident to act, free to decide, mentally strong, clear-minded, brave enough, open to change, emotionally stable, ready to move on, able to face it, strong inside, ready to act

5. Describing limits that need understanding and patience.

   In a broader sense, unable reminds us that everyone has limits. It encourages empathy, because behind being unable is often a story of effort, struggle, or circumstance.

   Instead of judging him, she tried to understand why he was unable to meet the deadline.
   The teacher showed patience with students who were unable to keep up at first.
   Sometimes being unable today simply means you will be able tomorrow.

   Synonyms: limited, restricted, challenged, not ready yet, facing limits, struggling, having difficulties, not capable right now, held back, dealing with obstacles, temporarily unable, facing barriers
   Antonyms: capable, empowered, ready, unrestricted, free to act, able to manage, strong enough, prepared, fully able, confident, able to succeed, unrestricted