Possible Clues:

• '___ born great', said Malvolio, the mathematician
• Hope one doesn't need 9 down in July
• Adder stretch standard from 1
• Theorem musician holds up part of the year
• Sunny season (allegedly)
• One of the Four Seasons
• Dumps drugs in me, disguised by lots of berries and bread
• and 12: Mum perusing a couple of Delia's originals when fixing dessert
• Hot time?
• Hot-weather season