beneficial
The definition for beneficial is "Helpful." Used in a sentence: there is no doubt that eating vegetables is beneficial to one's health.
eloquent
The definition for eloquent is "Fluent, expressive." Used in a sentence: Kim, an eloquent speaker, was the best choice to make the presentation for the group.
repentant
The definition for repentant is "Feeling regret." Used in a sentence: The repentant Dana admitted to cheating on the test.
stealth
The definition for stealth is "The act of moving secretly or unnoticed." Used in a sentence: The burglar took the ring by stealth, slipping it from the sleeping woman's finger.
untenable
The definition for untenable is "Not able to be defended." Used in a sentence: Rashid made the untenable statement that George Washington was the second president of the United States.