commemorate
The definition for commemorate is "To mark by a ceremony." Used in a sentence: Each year, the Franklins commemorate their anniversary by visiting the site of their first date.
condone
The definition for condone is "To treat as acceptable." Used in a sentence: Crystal condoned her friend's late arrival because she found it hard to be on time herself.
curtail
The definition for curtail is "To make less." Used in a sentence: Doreen decided to curtail her spending after she bounced a check.
illuminate
The definition for illuminate is "To make clear." Used in a sentence: Her excellent lecture illuminated the complicated subject of nuclear physics.
indecorous
The definition for indecorous is "In bad taste." Used in a sentence: My parents banned Chad from our house because of his indecorous behavior at dinner.