Geth Terminology:

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blocks - The number of blocks imported.

txs - The number of transactions being imported. (We're importing a full block here; 9280706 contains 188 transactions.)

mgas - Million gas. Those 188 transactions use 9,978,0779,978,077 gas.

elapsed - The time taken to download the block. This doesn't include the time taken to apply the state changes, which you've seen takes much longer.

mgasps - Million gas per second. We imported 9.978 Mgas of work in 2.180 seconds.

number - The block number.

hash - The hash of the block header.

dirty - This is less intuitive. It's a measure of the amount of state change (disk I/O) associated with the imported data. So importing this block will result in rewriting 662 MB of data.