Directly related to "tact":
* Tactful: Showing sensitivity and skill in dealing with others.
* Tactlessly: In a way that lacks sensitivity or skill in dealing with others.
* Tactics: Methods used to achieve a particular goal, especially in war or politics.
* Tactical: Relating to or characteristic of tactics.
Words with a similar meaning:
* Diplomatic: Skillful in dealing with people, especially in sensitive situations.
* Discreet: Prudent and careful in one's speech or actions, especially with regard to confidential matters.
* Considerate: Showing concern for the needs and feelings of others.
* Polite: Having or showing good manners.
Less direct but still related:
* Contact: The state of being in touch or communication.
* Contagious: Able to be spread from one person to another.
* Tangent: A line or plane that touches a curve or surface at one point.
Note: The root "tact" is often used in combination with prefixes like "con-" and "in-" to create new words with slightly different meanings.