Your grandfather works on the new york times crossword puzzle every day. he has been very good at solving the puzzle and nearly always does. his ability to remember the meaning of words has shown no decline as he has aged, and really shows very little decline for most older adults. what type of memory is this?

This is semantic memory.
Semantic memory actually refers to your 'general knowledge' - the information that you know about the world in general. The grandfather's semantic memory is quite strong and it doesn't seem to decline, which is why he is still so good at solving crossword puzzles. This refers to knowledge and memory that we accumulate throughout our lives. 

Ongoing civil wars western roman empire finally collapsed476 c.e. romulus, the last of theroman  emperors in  the west, was overthrown by the germanic leader odoacer, who became the first barbarian to rule in rome. the order that the  roman empire  had brought towestern  europe for 1000 years was no more.