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.
implausible
The definition for implausible is "Unbelievable." Used in a sentence: Claudia's implausible excuse failed to convince her teacher.
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.
prune
The definition for prune is "To reduce by removing excess." Used in a sentence: The candidate pruned his speech so he would not exceed the time limit.
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.