aerate
The definition for aerate is "To supply with air." Used in a sentence: Every spring, Soloman used his tiller to aerate the compact soil.
buffer
The definition for buffer is "Protective barrier." Used in a sentence: The dense trees acted as a buffer against the heavy rain.
discern
The definition for discern is "To recognize as separate as distinct." Used in a sentence: The pastry connoisseur was able to discern Swiss from Belgian chocolate.
dubious
The definition for dubious is "Questionable." Used in a sentence: Karl found Kevin's claim that he was sick dubious, as he had just seen him playing football.
manifest
The definition for manifest is "Obvious." Used in a sentence: James finally made his affection manifest when he handed Jessica a red rose.