- Rejoin implies an answer, originally to a reply, now often to an objection
- Retort suggests a reply, esp. one that is sharp or witty, provoked by a charge or criticism
- Reply in its strictest application refers to an answer that directly or in detail satisfies a question, charge, etc.
- Respond implies an appropriate reaction, either in words or action, made voluntarily or spontaneously to that which serves as a stimulus to respond to an appeal
- Answer implies saying, writing, or acting in return, as required by the situation or by courtesy to answer a letter, to answer the phone