What does the cryptic crossword clue "Acquire money and become more common (4,8)" mean?

The wordplay uses a charade (building blocks). GAIN (synonym="acquire") + CURRENCY (synonym="money") = GAINCURRENCY The answer is GAINCURRENCY.

Acquire money and become more common (4,8)

Guardian Cryptic #26837 | 11 Down | 2016-03-21 flower