beneficial
The definition for beneficial is "Helpful." Used in a sentence: there is no doubt that eating vegetables is beneficial to one's health.
exception
The definition for exception is "A case to which the rule does not apply." Used in a sentence: The teacher made an exception and let Gina eat her snack in class.
lenient
The definition for lenient is "Mild or tolerant." Used in a sentence: The judge issued a lenient sentence because it was Frank's first offense.
opportune
The definition for opportune is "Suitable or convenient." Used in a sentence: Quan stepped onto the platform at the most opportune time, just as the train pulled in.
repentant
The definition for repentant is "Feeling regret." Used in a sentence: The repentant Dana admitted to cheating on the test.